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DATA SHEET
BiCMOS INTEGRATED CIRCUIT
PC1934
DC-DC CONVERTER CONTROL IC
DESCRIPTION
The PC1934 is an IC that controls a low-voltage input DC-DC converter. This IC is suitable for an operation with 3-V, 3.3-V input or a lithium ion secondary battery input, because the minimum operation supply voltage is 2.5 V. Because of its wide operating voltage range, it can also be used to control DC-DC converters that use an AC adapter for input.
FEATURES
* Low supply voltage: 2.5 V (MIN.) * Operating voltage range: 2.5 to 20 V (breakdown voltage: 30 V) * Timer latch circuit for short-circuit protection. * Ceramic capacitor with low capacitance (0.1 F) can be used for short-circuit protection. * Open drain outputs (Each of the outputs can be used to control a step-down converter, a step-up converter and an inverted converter.) * Can control two output channels.
ORDERING INFORMATION
Part Number Package 16-pin plastic SSOP (5.72 mm (225)) 16-pin plastic TSSOP (5.72 mm (225))
PC1934GR-1JG PC1934GR-PJG
The information in this document is subject to change without notice. Before using this document, please confirm that this is the latest version.
Not all devices/types available in every country. Please check with local NEC representative for availability and additional information.
Document No. G13567EJ3V0DS00 (3rd edition) Date Published April 2000 NS CP (K) Printed in Japan
The mark 5 shows major revised points. 1998
PC1934
BLOCK DIAGRAM
Channel 2 VREF 16 DLY 15 IN2 14 II2 13 FB2 12 DTC2 11 MOS output Reference voltage section Timer latch for short-circuit protection section MOS input - + E/A2 - - + PWM2 OUT2 10 VCC 9
MOS output + Oscillation section - E/A1 + - - PWM1
MOS input
1 CT
2 RT
3 IN1
4 II1
5 FB1
6 DTC1
7 OUT1
8 GND
Channel 1
2
Data Sheet G13567EJ3V0DS00
PC1934
PIN CONFIGURATION (Top View)
16-pin plastic SSOP (5.72 mm (225)) * PC1934GR-1JG
16-pin plastic TSSOP (5.72 mm (225)) * PC1934GR-PJG
CT RT IN1 II1 FB1 DTC1 OUT1 GND
1 2 3 4 5 6 7 8
16 15 14 13 12 11 10 9
VREF DLY IN2 II2 FB2 DTC2 OUT2 VCC
PIN FUNCTIONS
Pin No. 1 2 3 Symbol CT RT IN1 Function Frequency setting capacitor connection Frequency setting resistor connection Channel 1 error amplifier non-inverted input 4 5 6 II1 FB1 DTC1 Channel 1 error amplifier inverted input Channel 1 error amplifier output Channel 1 dead time setting 12 13 14 FB2 II2 IN2 Channel 2 error amplifier output Channel 2 error amplifier inverted input Channel 2 error amplifier non-inverted input 7 OUT1 Channel 1 open drain output 15 DLY Delay capacitor connection of shortcircuit protection 8 GND Ground 16 VREF Reference voltage output Pin No. 9 10 11 Symbol VCC OUT2 DTC2 Power supply Channel 2 open drain output Channel 2 dead time setting Function
Data Sheet G13567EJ3V0DS00
3
PC1934
CONTENTS 1. ELECTRICAL SPECIFICATIONS ................................................................................................................ 5 2. CONFIGURATION AND OPERATION OF EACH BLOCK.................................................................... 10
2.1 Reference Voltage Generator ...........................................................................................................................10 2.2 Oscillator ...........................................................................................................................................................10 2.3 Under Voltage Lock-out Circuit ........................................................................................................................11 2.4 Error Amplifiers.................................................................................................................................................11 2.5 PWM Comparators............................................................................................................................................11 2.6 Timer Latch-Method Short Circuit Protection Circuit ....................................................................................11 2.7 Output Circuit....................................................................................................................................................11
3. NOTES ON USE........................................................................................................................................ 12
3.1 Setting the Output Voltage ...............................................................................................................................12 3.2 Setting the Oscillation Frequency ...................................................................................................................13 3.3 Preventing Malfunction of the Timer Latch-Method Short Circuit Protection Circuit..................................13 3.4 Connecting Unused Error Amplifiers ..............................................................................................................13 3.5 ON/OFF Control.................................................................................................................................................14 3.6 Notes on Actual Pattern Wiring........................................................................................................................14
4. APPLICATION EXAMPLE ......................................................................................................................... 15
4.1 Application Example.........................................................................................................................................15 4.2 List of External Parts ........................................................................................................................................15
5. PACKAGE DRAWINGS.............................................................................................................................. 16 6. RECOMMENDED SOLDERING CONDITIONS ....................................................................................... 18
4
Data Sheet G13567EJ3V0DS00
PC1934
1. ELECTRICAL SPECIFICATIONS
Absolute Maximum Ratings (unless otherwise specified, TA = 25 C)
Parameter Supply voltage Output voltage Output current (open drain output) Total power dissipation Operating ambient temperature Storage temperature Symbol VCC VO IO PT TA Tstg 417 -20 to + 85 -55 to + 150
PC1934GR-1JG
30 30 21
PC1934GR-PJG
Unit V V mA
400
mW C C
Caution
Product quality may suffer if the absolute maximum rating is exceeded even momentarily for any parameter. That is, the absolute maximum ratings are rated values at which the product is on the verge of suffering physical damage, and therefore the product must be used under conditions that ensure that the absolute maximum ratings are not exceeded.
Recommended Operating Conditions
Parameter Supply voltage Output voltage Output current Operating temperature Oscillation frequency Symbol VCC VO IO TA fOSC -20 20 MIN. 2.5 0 TYP. MAX. 20 20 20 +85 1000 Unit V V mA C kHz
Caution
The recommended operating range may be exceeded without causing any problems provided that the absolute maximum ratings are not exceeded. However, if the device is operated in a way that exceeds the recommended operating conditions, the margin between the actual conditions of use and the absolute maximum ratings is small, and therefore thorough evaluation is necessary. The recommended operating conditions do not imply that the device can be used with all values at their maximum values.
Data Sheet G13567EJ3V0DS00
5
PC1934
Electrical Characteristics (unless otherwise specified, TA = 25 C, VCC = 3 V, fOSC = 100 kHz)
Block Under voltage Lock-out section Reference Voltage section Parameter Start-up voltage Operation stop voltage Hysteresis voltage Reset voltage (timer latch) Reference voltage Line regulation Load regulation Temperature coefficient Oscillation section fOSC setting accuracy fOSC total stability Symbol VCC (L-H) VCC (H-L) VH VCCR VREF REGIN REGL VREF/T fOSC fOSC Conditions IREF = 0.1 mA IREF = 0.1 mA IREF = 0.1 mA IREF = 0.1 mA IREF = 1 mA 2.5 VVCC20 V 0.1 mAIREF1 mA -20 CTA+85 C, IREF = 0 A RT = 11 k, CT = 330 pF -20 CTA+85 C, 2.5 VVCC20 V Dead time control section Error Amplifier section Input bias current Low-level threshold voltage High-level threshold voltage Input offset voltage Input offset current Input bias current Common mode input voltage range Open loop gain Unity gain Maximum output voltage (+) Maximum output voltage (-) Output sink current Output source current Output section Drain cutoff current Output ON voltage Rise time Fall time Short-circuit Protection section Input sense voltage UV sense voltage Source current on short-circuiting Delay time Overall Circuit operation current IBD VTH (L) VTH (H) VIO IIO IB VIMC Av funity VOM VOM
+ -
MIN.
TYP. 1.57 1.5
MAX.
Unit V V mV V
30
70 1.0
2.0
2.1 2 2 0.5
2.2 12.5 7.5
V mV mV %
-15 -30
+15 +30
% %
0.4 Duty = 100 % Duty = 0 % -10 -100 -100 0 VO = 0.3 V VO = 0.3 V IO = -45 A IO = 45 A VFB = 0.5 V VFB = 1.6 V VO = 30 V RL = 150 RL = 150 RL = 150 0.5 0.6 1.0 CDLY = 0.1 F VCC = 3 V 1.4 0.2 50 60 0.63 0.8 1.6 50 2.2 0.8 1.6 70 80 1.5 2 0.02 1.4 -70 1.2 1.6
1.0
A
V V
+10 +100 +100 0.4
mV nA nA V dB MHz V
0.5
V mA
IOsink IOsource ILEAK VOL tr tf VTH VUV IOUV tDLY ICC
-45 100 0.6
A A
V ns ns
0.75 0.95 2.5
V V
A
ms
3.7
mA
Caution Connect a capacitor of 0.01 to 10 F to the VREF pin.
16
PC1934
8
CREF = 0.01 to 10 F
6
Data Sheet G13567EJ3V0DS00
Timing Charts
Channel 1 soft start DTC1 Normal operation Short-load Stop output
Channel 1 CT
FB1
VTH
OUT1
Data Sheet G13567EJ3V0DS00
ON OFF DTC2
Channel 2 CT
FB2
OUT2 ON OFF DLY VUV
Remark These timings are an example when the channel 1 output has been a short- load. The outputs of channel 1 and 2 are also stopped when a shortcircuit protection circuit starts operation by detecting a short- load of channel 2.
PC1934
7
PC1934
Typical Characteristic Curves (unless otherwise specified, VCC = 3 V, fOSC = 100 kHz, TA = 25 C) (Nominal)
PT vs TA 0.5 2.5 IREF = 0 A 0.4
PC1934GR-1JG 300 C/W
VREF vs VCC
Total power dissipation PT (W)
Reference voltage VREF (V)
2.0
0.3
PC1934GR-PJG 312.5 C/W
1.5
0.2 0.1
1.0 0.5
0
25 50 75 100 125 150 Operating ambient temperature TA (C) VREF vs TA
0
1 2 3 4 Supply voltage VCC (V) fOSC vs RT
5
2.13 IREF = 0 A
1000
Reference voltage VREF (V)
2.12 2.11 2.10 2.09 2.08 2.07 -25 0 25 50 75 100 Operating ambient temperature TA (C) fOSC vs TA
Oscillation frequency fOSC (kHz)
CT = 150 pF 100 CT = 330 pF 10 CT = 1500 pF
1
10 100 Timing resistance RT (k) VOL vs TA
1000
Oscillation frequency accuracy fOSC (%)
6
0.5 CT = 330 pF RT = 10 k IO = 20 mA
Output ON voltage VOL (V)
4 2 0 -2 -4
0.4
0.3
0.2 0.1 0 -25 0 25 50 75 100 Operating ambient temperature TA (C)
-6 -25 0 25 50 75 100 Operating ambient temperature TA (C)
8
Data Sheet G13567EJ3V0DS00
PC1934
Short-circuit protection circuit delay time tDLY (ms)
VOL vs IO 0.5 tDLY vs CDLY 600 500 400 300 200 100
Output ON voltage VOL (V)
0.4
0.3
0.2
0.1
0
4
8 12 16 Output current IO (mA) Av, vs f
20
0
0.2 0.4 0.6 0.8 1.0 DLY pin capacitor capacitance CDLY ( F) ICC vs VCC
100 80 60 40 Av 20 0 -20 100
180
4
Circuit operation ICC (mA)
135
3
45 0
Phase (deg)
Gain Av (dB)
90
2
1
-20 -90 10 M
1k
10 k 100 k 1 M Frequency f (Hz)
0
5
10 15 20 25 Supply voltage VCC (V)
30
Data Sheet G13567EJ3V0DS00
9
PC1934
2. CONFIGURATION AND OPERATION OF EACH BLOCK
Figure 2-1 Block Diagram
2 1
Oscillation section DTC1 FB1 II1 IN1 DTC2 FB2 II2 IN2 6 5 4 3 11 12 13 14 Error amplifier PWM comparator VREF 16 Under voltage lock-out section Output section Error amplifier PWM comparator Output section
RT CT
7
OUT1
10
OUT2
VCC
9
Reference voltage section
SCP comparator Q1 0.63 V DLY Q2
S
Q 8 Q GND
15 CDLY
Timer latch for short-circuit protection section
2.1
Reference Voltage Generator
The reference voltage generator is comprised of a band-gap reference circuit, and outputs a temperature-compensated reference voltage (2.1 V). The reference voltage can be used as the power supply for internal circuits, or as a reference voltage, and can also be accessed externally via the VREF pin (pin 16).
2.2
Oscillator
The oscillator self-oscillates if a timing resistor is attached to the RT pin (pin 2). Also, the oscillator outputs the symmetrical triangular waveform if a timing capacitor is attached to the CT pin (pin 1). This oscillator waveform is input to the non-inverted input pins of the two PWM comparators to determine the oscillation frequency.
10
Data Sheet G13567EJ3V0DS00
PC1934
2.3 Under Voltage Lock-out Circuit
The under voltage lock-out circuit prevents malfunctioning of the internal circuits when the supply voltage is low, such as when the supply voltage is first applied, or when the power supply is interrupted. When the voltage is low, the two output transistors are cut off at the same time.
2.4
Error Amplifiers
The circuits of the error amplifiers E/A1 and E/A2 are exactly the same. The first stage of the error amplifier is a Pchannel MOS transistor input. Be careful of the input voltage ranges (the common mode input voltage ranges are all 0 to 0.4 V (TYP .)).
2.5
PWM Comparators
The output ON duty is controlled according to the outputs of the error amplifiers and the voltage input to the Dead Time Control pin. A triangular waveform is input to the non-inverted pin, and the error amplifier output and Dead Time Control pin voltage are input to the inverted pins of the PWM comparators. Therefore, the output transistor ON period is the period when the triangular waveform is higher than the error amplifier output and Dead Time Control pin voltage (refer to Timing Charts).
2.6
Timer Latch-Method Short Circuit Protection Circuit
When the converter outputs either a channel or both channels drop, the FB outputs of the error amplifiers of those outputs go low. If the FB output goes lower than the timer latch input detection voltage (VTH = 0.63 V)), then the output of the SCP comparator goes low, and Q1 goes off. When Q1 turns OFF, the constant-current supply charges CDLY via the DLY pin. The DLY pin is internally connected to a flip-flop. When the DLY pin voltage reaches the UV detection voltage (VUV = 0.8 V (TYP the output Q of the flip-flop goes .)), low, and the output stage of each channel is latched to OFF (refer to Figure 2-1 Block Diagram). Make the power supply voltage briefly less than the reset voltage (VCCR, 1.0 V TYP to reset the latch circuit when the .) short-circuit protection circuit has operated.
2.7
Output Circuit
The output circuit has an N-channel open-drain output providing an output withstand voltage of 30 V (absolute maximum rating), and an output current of 21 mA (absolute maximum rating).
Data Sheet G13567EJ3V0DS00
11
PC1934
3. NOTES ON USE
3.1
Setting the Output Voltage
Figure 3-1 illustrates the method of setting the output voltage. The output voltage is obtained using the formula shown in the figure. The common mode input voltage range of the error amplifier is 0 to 0.4 V (TYP for both the error amplifiers, E/A1 and .) E/A2. Therefore, select a resistor value that gives this voltage range.
Figure 3-1 Setting the Output Voltage
(1) When setting a positive output voltage using error amplifier E/A1.
VOUT (positive voltage)
R4 VOUT = 1 + R1 * * VREF R2 R3 + R4
R1
16
VREF
4
R3 R2 R4
CNF
3
E/A1
RNF
5
(2) When setting a negative output voltage using error amplifier E/A2.
16
VREF
R1
13
R2
R3 R4
CNF
14
E/A2
RNF
12
VOUT (negative voltage)
VOUT = R1R4-R2R3 * VREF R1 (R3+R4)
12
Data Sheet G13567EJ3V0DS00
PC1934
3.2 Setting the Oscillation Frequency
Choose RT according to the oscillation frequency (fOSC) vs timing resistor (CT, RT) characteristics (refer To Typical Characteristics Curves fOSC vs CT, RT). The formula below (3-1) gives an approximation of fOSC. However, the result of formula 3-1 is only an approximation, and the value must be confirmed in actual operation, especially for high-frequency operation.
fOSC [Hz] 0.375/(CT [F] x RT []) (3-1)
3.3
Preventing Malfunction of the Timer Latch-Method Short Circuit Protection Circuit
The timer latch short-circuit protection circuit operates when the error amplifier outputs (pin 5 and 12) goes below approximately 0.63 V, and cuts off the output. However, if the rise of the power supply voltage is fast, or if there is noise on the DLY pin (pin 15), the latch circuit may malfunction and cut the output off. To prevent this, lower the wiring impedance between the DLY pin and the GND pin (pin 8), and avoid applying noise to the DLY pin.
3.4
Connecting Unused Error Amplifiers
When one of the two control circuits is used, connect the circuit so that the output of the error amplifier of unused circuit is high. Figure 3-2 shows examples of how to connect unused error amplifiers.
Figure 3-2 Examples of Connecting Unused Error Amplifiers
(1) Error amplifier E/A1
16
VREF
3
E/A1
4
5
6
DTC1
(2) Error amplifier E/A2
16
VREF
14
E/A2
13
12
11
DTC2
Data Sheet G13567EJ3V0DS00
13
PC1934
3.5 ON/OFF Control
The ON/OFF control method of the output oscillation is to input the ON/OFF signal from ON as shown in Figure 3-3. The PWM converter can be turned ON/OFF by controlling the level of the DTC pin. However, it is necessary to keep the level of the FB output high so that the timer latch does not start when the PWM converter is OFF. In this circuit example, the FB output level is controlled by controlling the level of the II pin.
Figure 3-3 ON/OFF Control
VO VREF FB II
-
R1
R5
SCP comparator (common to each channel)
+ -
DLY Q CDLY
Q3
R2 R6
IN
Error 0.3 V amplifier
+
0.63 V
VREF Q2 R3 C1 DTC ON Q1 R4
- - +
To output stage
PWM comparator Oscillation section (common to each channel)
(1) When ON is high: OFF status Q1: ON Q2: ON DTC pin: High level Output duty of PWM comparator: 0 % Q3: ON II pin: Low level FB output: High level SCP comparator output: High level Q is ON. Timer latch stops.
(2) When ON3 is low: ON status Q1: OFF Q2 is OFF C1 is charged in the sequence of [VREF C1 R4] DTC pin voltage drops. Soft start . Q3: OFF II pin: High level FB output: Low level SCP comparator output: Low level Q: OFF Charging CDLY starts (timer latch start).
Caution Keep the high-level voltage of the DTC pin at 1.6 V or higher and the low-level voltage of the II pin within (R6/(R5+R6))*VREF. The maximum voltage that is applied to the II pin must be equal to or lower * than VREF.
3.6
Notes on Actual Pattern Wiring
When actually carrying out the pattern wiring, it is necessary to separate control-related grounds and power-related grounds, and make sure that they do not share impedances as far as possible. In addition, make sure the high-frequency impedance is lowered using capacitors and other components to prevent noise input to the VREF pin.
14
Data Sheet G13567EJ3V0DS00
PC1934
4. APPLICATION EXAMPLE
4.1
Application Example
Figure 4-1 shows an example circuit for obtaining 5 V/50 mA from a +3 V power supply.
Figure 4-1 Chopper-Method Step-up/Inverting-Type Switching Regulator
VIN = 3 V
C1 1 F
COM
C2 10 F R24 2 k R28 15 k R27 5 k C23 3300 pF R25 12 k R29 510 R210 470 R212 10 L11 100 H R111 Q23 100 Q23 Q23 R214 10 k C24 68 F R22 5 k D21
R23 12 k C21 R26 1 F 10 k
CH2 VO = +5.0 V
R21 IO = 50 mA 47 k
CDLY 0.1 F
16
15
14
IN2
13
II2
12
11
10
9
R211 24 k C23 100 pF
VREF DLY
FB2 DTC2 OUT2 VCC
C11 0.1 F
GND
PC1934
D11 Q13 CT RT IN1 II1 FB1 DTC1 OUT1 GND R111 470
1
CT 100 pF R18 2 k R18 12 k R16 10 k C11 1 F
2
3
4
5
6
7
8
R19 80 R111 10
Q11 R113 10 k R112 20 Q12 C113 100 pF
CH1 VO = -5.0 V IO = 50 mA
R12 20 k
RT 5.1 k R18 12 k R17 5 k
C23 3300 pF
L11 100 H
C14 68 F
R15 12 k
GND
R11 5.1 k
4.2
List of External Parts
The list below shows the external parts.
Table 4-1 List of External Parts
Symbol C2 C14 D11 L11 Q11, Q12 Q13 C21 D21 L21 Q21, Q22 Q23 100 H 68 F 100 H Parameter 10 F 68 F Function Input stable capacitor Output capacitor Schottkey diode Choke inductor Buffer transistor Switching transistor Output capacitor Schottkey diode Choke inductor Buffer transistor Switching transistor Part number 25SC10M 20SA68M D1FS4 636FY-101M Maker SANYO SANYO SHINDENGEN TOKO NEC NEC SANYO SHINDENGEN TOKO NEC NEC D73F series Transistor array OS-CON, SA series D73F series Transistor array Remark OS-CON, SC series OS-CON, SA series
PA609T
2SB1572 20SA68M D1FS4 636FY-101M
PA609T
2SD2403
Remarks 1. The capacitors that are not specified in the above list are multilayer ceramic capacitors. 2. The resistors that are not specified in the above list are 1/4W resistors.
Data Sheet G13567EJ3V0DS00
15
PC1934
5. PACKAGE DRAWINGS
16-PIN PLASTIC SSOP (5.72 mm (225))
16 9
detail of lead end
P
1 A
8
F G
H I J
S C D E
NOTE Each lead centerline is located within 0.10 mm of its true position (T.P.) at maximum material condition.
ITEM A B C D E F G H I J K L M N P MILLIMETERS 5.20.3 0.475 MAX. 0.65 (T.P.) 0.220.8 0.1250.075 1.5650.235 1.44 6.20.3 4.40.2 0.90.2 0.17 +0.08 -0.07 0.50.2 0.10 0.10 55 P16GM-65-225B-4
B
M
L K
N
S
M
16
Data Sheet G13567EJ3V0DS00
PC1934
16-PIN PLASTIC TSSOP (5.72 mm (225))
16 9 detail of lead end F G R
P
L S
1
8
E
A A' S
H I J
C D
NOTE
K B
N
S
M
M
Each lead centerline is located within 0.10 mm of its true position (T.P.) at maximum material condition.
ITEM A A' B C D E F G H I J K L M N P R S
MILLIMETERS 5.150.15 5.00.1 0.375 MAX. 0.65 (T.P.) 0.24 +0.06 -0.04 0.09 +0.06 -0.04 1.01 +0.09 -0.06 0.92 6.40.2 4.40.1 1.00.2 0.145+0.055 -0.045 0.5 0.10 0.10 3 +5 -3 0.25 0.60.15 S16GR-65-PJG-1
Data Sheet G13567EJ3V0DS00
17
PC1934
6. RECOMMENDED SOLDERING CONDITIONS
Recommended solder conditions for this product are described below. For details on recommended soldering conditions, refer to Information Document "Semiconductor Device Mounting Technology Manual" (C10535E). For soldering methods and conditions other than those recommended, consult NEC.
Surface Mount Type
PC1934GR-1JG: 16-pin plastic SSOP (5.72 mm (225)) PC1934GR-PJG: 16-pin plastic TSSOP (5.72 mm (225))
Soldering Method Soldering Conditions Symbol of Recommended Conditions Infrared reflow Package peak temperature: 235 C, Time: 30 seconds MAX. (210 C MIN.), Number of times: 3 MAX. VPS Package peak temperature: 215 C, Time: 40 seconds MAX. (200 C MIN.), Number of times: 3 MAX. Wave soldering Soldering bath temperature: 260 C MAX., Time: 10 seconds MAX., Number of times: 1, Preheating temperature: 120 C MAX. (package surface temperature) WS60-00-1 VP15-00-3 IR35-00-3
Caution Do not use two or more soldering methods in combination.
18
Data Sheet G13567EJ3V0DS00
PC1934
NOTES FOR BiCMOS DEVICES
1 PRECAUTION AGAINST ESD FOR SEMICONDUCTORS Note:
Strong electric field, when exposed to a device, can cause destruction of the gate oxide and ultimately degrade the device operation. Steps must be taken to stop generation of static electricity as much as possible, and quickly dissipate it once, when it has occurred. Environmental control
must be adequate. When it is dry, humidifier should be used. It is recommended to avoid using insulators that easily build static electricity. Semiconductor devices must be stored and transported in an anti-static container, static shielding bag or conductive material. All test and measurement tools including work bench and floor should be grounded. The operator should be grounded using wrist strap. Semiconductor devices must not be touched with bare hands. Similar precautions need to be taken for PW boards with semiconductor devices on it. 2 HANDLING OF UNUSED INPUT PINS Note:
No connection for device inputs can be cause of malfunction. If no connection is provided to the input pins, it is possible that an internal input level may be generated due to noise, etc., hence causing malfunction. Input levels of devices must be fixed high or low by using a pull-up or pulldown circuitry. Each unused pin should be connected to VDD or GND with a resistor, if it is considered to have a possibility of being an output pin. All handling related to the unused pins must be judged device by device and related specifications governing the devices.
3
STATUS BEFORE INITIALIZATION OF BiCMOS DEVICES Note:
Power-on does not necessarily define initial status of device. Production process of BiCMOS does not define the initial operation status of the device. Immediately after the power source is turned ON, the devices with reset function have not yet been initialized. Hence, power-on does not guarantee out-pin levels, I/O settings or contents of registers. Device is not initialized until the reset signal is received. Reset operation must be executed immediately after power-on for devices having reset function.
Data Sheet G13567EJ3V0DS00
19
PC1934
[MEMO]
* The information in this document is subject to change without notice. Before using this document, please confirm that this is the latest version. * No part of this document may be copied or reproduced in any form or by any means without the prior written consent of NEC Corporation. NEC Corporation assumes no responsibility for any errors which may appear in this document. * NEC Corporation does not assume any liability for infringement of patents, copyrights or other intellectual property rights of third parties by or arising from use of a device described herein or any other liability arising from use of such device. No license, either express, implied or otherwise, is granted under any patents, copyrights or other intellectual property rights of NEC Corporation or others. * Descriptions of circuits, software, and other related information in this document are provided for illustrative purposes in semiconductor product operation and application examples. The incorporation of these circuits, software, and information in the design of the customer's equipment shall be done under the full responsibility of the customer. NEC Corporation assumes no responsibility for any losses incurred by the customer or third parties arising from the use of these circuits, software, and information. * While NEC Corporation has been making continuous effort to enhance the reliability of its semiconductor devices, the possibility of defects cannot be eliminated entirely. To minimize risks of damage or injury to persons or property arising from a defect in an NEC semiconductor device, customers must incorporate sufficient safety measures in its design, such as redundancy, fire-containment, and anti-failure features. * NEC devices are classified into the following three quality grades: "Standard", "Special", and "Specific". The Specific quality grade applies only to devices developed based on a customer designated "quality assurance program" for a specific application. The recommended applications of a device depend on its quality grade, as indicated below. Customers must check the quality grade of each device before using it in a particular application. Standard: Computers, office equipment, communications equipment, test and measurement equipment, audio and visual equipment, home electronic appliances, machine tools, personal electronic equipment and industrial robots Special: Transportation equipment (automobiles, trains, ships, etc.), traffic control systems, anti-disaster systems, anti-crime systems, safety equipment and medical equipment (not specifically designed for life support) Specific: Aircraft, aerospace equipment, submersible repeaters, nuclear reactor control systems, life support systems or medical equipment for life support, etc. The quality grade of NEC devices is "Standard" unless otherwise specified in NEC's Data Sheets or Data Books. If customers intend to use NEC devices for applications other than those specified for Standard quality grade, they should contact an NEC sales representative in advance.
M7 98. 8

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