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FUJITSU SEMICONDUCTOR DATA SHEET
DS04-27216-4E
ASSP For Power Supply Applications
BIPOLAR
Switching Regulator Controller
MB3817
s DESCRIPTION
The MB3817 is a pulse width modulator (PWM) type switching regulator controller IC designed for low-voltage and high-speed operation. This can be used in applications as down-conversion or down/up-conversion (Zeta method) . With fewer external components and faster operating speed, the MB3817 enables reduction in power supply unit size, making it ideal for use with internal power supplies in compact, high-performance portable devices.
s FEATURES
* * * * * * * * * Wide range of operating power supply voltages : 2.5 V to 18 V Built-in high-precision reference voltage generator : 1.5 V 2% High speed operation is possible : Max 500 kHz Wide input voltage range of error amplifier : 0 V to VCC - 0.9 V Built-in soft start function Built-in timer/latch-actuated short-circuiting protection circuit Totem-pole type output with adjustable on/off current (for PNP transistors) Built-in standby function Small package : SSOP-16P (FPT-16P-M05)
s PACKAGE
16-pin Plastic SSOP
(FPT-16P-M05)
MB3817
s PIN ASSIGNMENT
(TOP VIEW)
CT
1
16
VREF
RT +IN -IN
2
15
CTL
3
14
CSCP
4
13
CS
FB
5
12
GND
DTC
6
11
VE
CB1
7
10
OUT
CB2
8
9
VCC
(FPT-16P-M05)
2
MB3817
s PIN DESCRIPTION
Pin no. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Pin name CT RT +IN -IN FB DTC CB1 CB2 VCC OUT VE GND CS CSCP CTL VREF I/O I I O I O I O Descriptions This terminal connects to a capacitor for setting the triangular-wave frequency. This terminal connects to a resistor for setting the triangular-wave frequency. Error amplifier non-inverted input terminal Error amplifier inverted input terminal Error amplifier output terminal Dead time control terminal Boot capacitor connection terminal Boot capacitor connection terminal Power supply terminal Totem-pole type output terminal Output current setting terminal Ground terminal Soft start setting capacitor connection terminal Short detection setting capacitor connection terminal Power supply control terminal When this terminal is High, IC is inactive state When this terminal is Low, IC is standby state Reference voltage output terminal
3
MB3817
s BLOCK DIAGRAM
OUT FB 5 -IN +IN DTC 4 3 6 CS CS 13 1 A Q1 Soft Start - Comp. + (0.9 V) - + 1.5 V SCP 1 A -1.4 V -1.0 V OSC bias RS Latch 2 CT RT UVLO Q2 Q3 bias VCC SCP Comp. Q5 Q6 D1 (0.5 V) Error - Amp. + PWM + Comp. + + - OFF current setting block
CB1 7 8 CB2 9 Q4 10 OUT VCC
11 VE
Power Ref (1.5 V) ON/OFF 12 GND
15
CTL
1
14 16 CSCP VREF
4
MB3817
s ABSOLUTE MAXIMUM RATINGS
Parameter Power supply voltage Power dissipation Storage temperature Symbol VCC PD Tstg Condition Ta +25 C Rating Min -55 Max 20 440* +125 Unit V mW C
* : The package is mounted on the epoxy board (10 cm x 10 cm) . WARNING: Semiconductor devices can be permanently damaged by application of stress (voltage, current, temperature, etc.) in excess of absolute maximum ratings. Do not exceed these ratings.
s RECOMMENDED OPERATING CONDITIONS
Parameter Power supply voltage Reference voltage output current Error amp. input voltage Control input voltage Output current Timing capacitance Timing resistance Oscillation frequency Soft start capacitance Short detection capacitance Boot capacitance Operating temperature Symbol VCC IOR VIN VCTL IO CT RT fOSC CS CSCP CB Ta Condition Value Min 2.5 -1 0 0 3 150 5.1 10 -40 Typ 6.0 200 0.1 0.1 +25 Max 18 0 VCC - 0.9 18 30 1500 100 500 1.0 1.0 0.1 +85 Unit V mA V V mA pF k kHz F F F C
WARNING: The recommended operating conditions are required in order to ensure the normal operation of the semiconductor device. All of the device's electrical characteristics are warranted when the device is operated within these ranges. Always use semiconductor devices within their recommended operating condition ranges. Operation outside these ranges may adversely affect reliability and could result in device failure. No warranty is made with respect to uses, operating conditions, or combinations not represented on the data sheet. Users considering application outside the listed conditions are advised to contact their FUJITSU representatives beforehand.
5
MB3817
s ELECTRICAL CHARACTERISTICS
(VCC = 6 V, Ta = +25 C) Parameter Output voltage Output temperature stability Reference section (Ref) Input stability Load stability Short circuit output current Under voltage Threshold voltage lockout protection Hysteresis width section (UVLO) Reset voltage Threshold voltage Soft start section (CS) Input standby voltage Charge current Threshold voltage Short circuit detection section (SCP) Input standby voltage Input latch voltage Input source current Oscillator frequency Triangular waveform oscillator section (OSC) Frequency voltage stability Frequency temperature stability Symbol VREF VREF/ VREF Line Load IOS VTH VTL VH VR VT0 VT100 VSTB ICHG VTH VSTB VI II fOSC f/fdv f/fdt Pin no. 16 16 16 16 16 13 13 13 13 10 10 13 13 14 14 14 14 10 10 10 Condition Ta = -40C to +85C VCC = 2.5 V to 18 V IOR = 0 mA to -1 mA VREF = 1 V VCC = VCC = Duty cycle = 0% Duty cycle = 100% CT = 330 pF RT = 6.2 k VCC = 3.6 V to 16 V Ta = -40C to +85C Value Min 1.47 -10 1.5 0.1 0.6 0.9 -1.4 0.60 -1.4 450 Typ 1.50 0.5* 2 2 -5 2.0 1.8 0.2 1.0 1.0 1.4 50 -1.0 0.65 50 50 -1.0 500 1 1* Max 1.53 10 10 -2 2.3 1.5 100 -0.6 0.70 100 100 -0.6 550 10 Unit V % mV mV mA V V V V V V mV A V mV mV A kHz % %
* : Standard design value.
(Continued)
6
MB3817
(Continued)
Pin no. (VCC = 6 V, Ta = +25 C) Parameter Input offset voltage Input offset current Input bias current Common mode input voltage range Error amp. section (Error Amp.) Common mode rejection ratio Voltage gain Frequency bandwidth Maximum output voltage width Output sink current Output source current Threshold voltage Dead time control section (DTC) Symbol VIO IIO II VCM CMRR AV BW VOM+ VOM IO
+ -
Condition
Value Min -200 0 60 60 1.8 60 0.9 70 -500 0.9 60 18 2.1 0 Typ -100 100 100 800* 2.0 50 120 -2.0 1.0 1.4 80 -250 1.0 1.4 120 -2.0 30 -100 100 2.7 Max 10 100 VCC - 0.9 500 -0.6 1.5 90 1.5 -0.6 42 -50 10 18 0.7 200 10 4.0
Unit mV nA nA V dB dB kHz V mV A mA V V % nA V V A mA mA mA A V V A A mA
3, 4 VFB = 1.2 V 3, 4 VFB = 1.2 V 3, 4 VFB = 1.2 V 3, 4 5 5 5 5 5 5 5 10 10 10 6 10 10 5 5 10 10 10 11 11 15 9 9 DC DC AV = 0 dB VFB = 1.2 V VFB = 1.2 V Duty cycle = 0% Duty cycle = 100% VDTC = VREF x 0.88 CT = 330 pF, RT = 6.2 k VDTC = 0 V Duty cycle = 0% Duty cycle = 100% RE = 15 k Duty 5 % VCC = 18 V, VO = 18 V VCTL = 5 V VCTL = 0 V Output "H"
IO- VT0 VT100 Dtr IDTC VT0 VT100 II
+
ON duty cycle Input current
PWM comparator section (PWM Comp.)
Threshold voltage Input sink current Input source current Output sink current Output source current Standby leakage current
II- IO+ IO- ILO VON VOFF II ICCS ICC
Output section (OUT)
Control section (CTL) Input current Standby current
Input on condition Input off condition
Power supply current * : Standard design value.
7
MB3817
s TYPICAL CHARACTERISTICS
Power supply current vs. power supply voltage
5 Power supply current ICC (mA) 4 3 Ta = +25 C Reference voltage VREF (V) 2.0
Reference voltage vs. power supply voltage
Ta = +25 C IOR = 0 mA
1.5
1.0
2 1 0 0 2 4 6 8 10 12 14 16 Power supply voltage VCC (V) 18 20
0.5
0.0 0 2 4 6 8 10 12 14 16 Power supply voltage VCC (V) 18 20
Reference voltage vs. ambient temperature
1.55 1.54 Reference voltage VREF (V) 1.53 1.52 1.51 1.50 1.49 1.48 1.47 1.46 1.45 -60 -40 -20 0 20 40 60 80 100 VCC = 6 V IOR = 0 mA
Ambient temperature Ta (C)
Reference voltage vs. control voltage
500 1.7 Reference voltage VREF (V) 1.6 1.5 1.4 1.3 0 0 1 2 3 4 5 0 VCC = 6 V Ta = +25 C IOR = 0 mA 400 300 200 100
Control current vs. control voltage
VCC = 6 V Ta = +25 C
Control current ICTL (A)
4
8
12
16
20
Control voltage VCTL (V)
Control voltage VCTL (V)
(Continued)
8
MB3817
Triangular wave frequency fOSC (Hz)
10 M VCC = 6 V Ta = +25 C 1M
Triangular wave maximum amplitude voltage VCT (V)
Triangular wave frequency vs. timing resistance
Triangular wave maximum amplitude voltage vs. timing capacitance
1.8 1.6 1.4 1.2 1.0 0.8 0.6 10 VCC = 6 V Ta = +25 C RT = 6.2 k
100 k
10 k CT = 15000 pF 1k 1k 10 k
CT = 150 pF CT = 1500 pF
100 k
1M
102
103
104
105
Timing resistance RT ()
Timing capacitance CT (pF)
Duty vs. triangular wave frequency
100 80 Duty Dtr (%) 60 40 20 0 VCC = 6 V Ta = +25 C RT = 6.2 k VDTC = VREF x 0.88 1000 Triangular wave cycle tOSC (s)
Triangular wave cycle vs. timing capacitance
100 VCC = 6 V Ta = +25 C RT = 6.2 k
10
1
0.1 1k 10 k 100 k 1M 10 M 10 102 103 104 Triangular wave frequency fOSC (Hz) Timing capacitance CT (pF)
105
Frequency stability vs. ambient temperature
10.00 VCC = 6 V fOSC = 500 kHz (CT = 330 pF, RT = 6.2 k)
Frequency stability (%)
5.00
0.00
-5.00
-10.00 -60
-40
-20
0
20
40
60
80
100
Ambient temperature Ta (C)
(Continued)
9
MB3817
(Continued)
Error amp. frequency
50 40 30 20 AV (dB) 10 0 -10 -20 -30 -40 -50 1k 10 k 100 k Frequency fOSC (Hz) 1M AV Ta = +25 C 225 180 135 90 (deg) 45 0 -45 -90 -135 -180 -225 10 M 11 k -+ 10 F 3 11 k VREF Error Amp. 2.4 k 4 240 k
* Measurement circuit
VCC = 6 V
- 5 +
Output current setting pin voltage vs. output current setting pin current
Output current setting pin voltage VE (V) 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0 -10 -20 -30 -40 -50 VCC = 6 V Ta = +25 C
Power dissipation vs. ambient temperature
500 Power dissipation PD (mW) 440 400 300 200 100 0 -40
-20
0
20
40
60
80
100
120
Output current setting pin current IE (mA)
Ambient temperature Ta (C)
10
MB3817
s FUNCTIONAL DESCRIPTION
1. Switching Regulator Functions
(1) Reference voltage circuit (Ref) The reference voltage circuit generates a temperature-compensated stable voltage ( = 1.50 V) . This reference : voltage is used as the reference voltage and bias level for the power control unit. (2) Triangular-wave oscillator circuit By connecting a timing capacitor and a resistor to the CT (pin1) and the RT (pin2) terminals, it is possible to generate any desired triangular oscillation waveform. (3) Error amplifier The error amp. is an amplifier circuit that detects the output voltage from the switching regulator and produces the PWM control signal. The broad in-phase input voltage range of 0 V to Vcc - 0.9 V provides easy setting from external power supplies and enables use with applications such as DC motor speed control systems. Also, it is possible to provide stable phase compensation for a system by setting up any desired level of loop gain, by connecting feedback resistance and a capacitor between the error amp. output terminal (FB terminal (pin 5) ) and the inverse input terminal (-IN terminal (pin 4) ) . (4) PWM comparator (PWM Comp.) This is a voltage comparator with one inverted input and three non-inverted inputs, and operates as a voltagepulse width modulator controlling output duty in relation to input voltage. The output transistor is turned on during the interval in which the triangular waveform is lower than any of three voltages : the error amp. output voltage (FB terminal (pin 5) ) , soft start set voltage (CS terminal (pin 13) ) , or dwell time setting voltage (DTC terminal (pin 6) ) . (5) Output circuits (OUT) The output circuit has totem pole type configuration, and can drive an external PNP transistor. The on current value can be set up to a maximum of 30 mA using the resistance (RE) connected to the VE terminal (pin 11) . The off current is set by connecting a bootstrap capacitor CB between the CP1 terminal (pin 7) and CP2 terminal (pin 8) .
2. Power Supply Control Functions
The output is switched on and off according to the voltage level at the CTL terminal (pin 15) . CTL terminal voltage level Channel on/off status L ( 0.7 V) H ( 2.1 V) * : Supply current in standby mode is 10 A or less. Standby mode* Operating mode
11
MB3817
3. Protective Circuit Functions
(1) Soft start and short protection circuits (CS, SCP) Soft starting, by preventing a rush current at power-on, can be provided by connecting a capacitor CS to the CS terminal (pin 13) . After the soft start operation is completed, the CSCP terminal (pin 14) is held at "L" level (standby voltage VSTB), which functions as short detection standby mode. If an output short causes the error amp. output to rise above 1.5 V, capacitor CSCP begins charging, and after reaching threshold voltage VTH of 0.65 V causes the OUT terminal (pin 10) to be fixed at "H" level and the dwell time to be set to 100%, and the CSCP terminal (pin 14) is held at "L" level. Once the protection circuit has been activated, the power supply must be reset to restore operation. (2) Low input voltage error prevention circuit (UVLO) Power-on surges and momentary drops in power supply voltage can cause errors in control IC operation, which can destroy or damage systems. The low input voltage error protection circuit compares the supply voltage to the internal reference voltage, and sets the OUT terminal (pin 10) to "H" level in the event of a drop in supply voltage. Operation is restored when the power supply voltage returns above the threshold voltage of the low input voltage error prevention circuit.
12
MB3817
s SETTING OUTPUT VOLTAGE
* Output voltage VO is plus
VO+
R1 -IN 4 +IN R2 3 Error Amp. - + VO+ = VREF R2 (R1 + R2)
VREF
* Output voltage VO is minus
VREF
R2
R
-IN 4 +IN 3
Error Amp. - + VO- = - VREF 2 x R2 (R1 + R2) + VREF
R1
R
VO-
s OSCILATOR FREQUENCY SETTING
The oscillator frequency can be set by connecting a timing capacitor (CT) to the CT terminal (pin1) and a timing resistor (RT) to the RT terminal (pin2) . Oscillator frequency : fOSC fOSC (kHz) = : 1023000 CT (pF) *RT (k)
13
MB3817
s METHOD OF SETTING THE OUTPUT CURRENT
The output circuit is comprised of a totem-pole configuration. Its output current waveform is such that the ONcurrent value is set by constant current and the OFF-current value is set by a time constant. These output currents are set using the equations below. 500 ON current : IO+ [mA] = : (Voltage on output current-setting pin VE = 0.5 V) RE [] OFF current : OFF-current time constant = proportional to the value of CB * Output circuit
7 8 CB2 Outside putting PNP transistor OFF current setting block 9 Q4 10 Q6 Q5 D1 (0.5 V) 11 VCC OFF current OUT ON current RE VE CB1 CB
* Output current waveform
ON current
Output current
0
OFF current
t
14
MB3817
* Voltage and current waveforms on output terminal
4 2 VO (V) 0 -2 -4 40 IO (mA) 20 0 -20 VCC = 3 V
0
2
4 t (s)
6
8
10
* Measuring circuit diagram
7 8
CB1 CB 1000 pF CB2 VCC VCC 2S81121S U1FWJ44N (5.0 V)
9
35 k OUT RE 22 F VE 16 VO 22 F 10
15 k
11
15
MB3817
s METHOD OF SETTING THE SHORT DETECTION TIME
The error amp. output is connected to the inverted input of the short detector comparator circuit (SCP Comp.) , where it is constantly compared to the reference voltage of approximately 1.5 V that is connected to the noninverted input. If the switching regulator load conditions are stabilized, the short detector comparator output is at "H" level, transistor Q3 is on, and the CSCP terminal (pin14) holds the input standby voltage VSTB which is 50 mV. If load conditions change rapidly due to a cause such as a load short, so that output voltage falls, the short detector comparator circuit output changes to "L" level. When this happens, transistor Q3 turns off and the short detector capacitor CSCP connected externally to the CSCP terminal starts charging from the input source current II, which is -1.0 A. Short detection time (tPE) tPE [s] = 0.65 x CSCP [F] : When the short detector capacitor CSCP has been charged to the threshold voltage VTH, which is 0.65 V, the SR latch is set, and the external PNP transistor is turned off (setting dwell time to 100%) . At this time, the SR latch input is closed, and the CSCP terminal is set to input latch voltage VI which is 50 mV. * Short protection circuit
FB 5 -IN +IN 4 3 - + Error Amp. + + + - PWM Comp. 9 Q4 10 OUT Q6 SCP Comp. Q5 D1 (0.5V) 11 VE RE VCC Outside putting PNP transistor OFF current setting block
- +
1.5 V
1 A bias RS Latch UVLO Q2 Q3
14 CSCP
16
MB3817
s TREATMENT WHEN NOT USING CSCP
When you do not use the timer/latch-actuated short-circuiting protection circuit, connect the CSCP terminal (pin 14) to GND. * Treatment when not using CSCP
14
CSCP
17
MB3817
s METHOD OF SETTING SOFT START TIME
To protect against surge currents when the IC is turned on, a soft start setting can be made by connecting a soft start capacitor (CS) to the CS terminal (pin 13) . When the IC starts up (CTL terminal (pin 15) to "H" level, Vcc UVLO threshold voltage VTH) the transistor Q1 turns off and the soft start capacitor (CS) connected to the CS terminal begins charging from the charge current ICHG which is -1.0 A. At this time, if the CS terminal voltage is less than 0.9 V, the soft start comparator circuit output goes to "H" level, transistor Q2 turns on and the CSCP terminal (pin 14) holds input standby voltage VSTB which is 50 mV so that the short protection circuit is not activated. When the CS terminal voltage is greater than or equal to 0.9 V, transistor Q2 turns off, the PWM comparator circuit compares the CS terminal voltage with the triangular wave and changes the ON duty of the OUTPUT terminal, thus achieving a soft start. Note that the soft start time is determined by the following formula. Soft start time (time before output ON duty reaches 50%) tS [ms] = 1.2 x CS [F] : * Soft start circuit
+ + + -
PWM Comp.
OFF current setting block
9 Q4 10 OUT VCC
Outside putting PNP transistor
1 A CS 13 Q1 - + (0.9 V) 1 A bias RS Latch UVLO Q2 Q3 Soft Start Comp. Q5 D1 (0.5V)
Q6 11 VE
RE
14 CSCP
18
MB3817
s TREATMENT WHEN NOT USING CS
When not using the soft start function, the CS terminal (pin 13) should be left open.
* When no soft start time is set
Open 13 CS
19
MB3817
s METHOD OF SETTING THE DEAD TIME
When the device is set for step-up inverted output based on the flyback method, the output transistor is fixed to a full-on state (ON-duty = 100%) at power switch-on. To prevent this problem, you may determine the voltages on the DTC terminals (pin 6) from the VREF voltage so you can easily set the output transistor's dead time (maximum ON-duty) independently for each channel as shown below. When the voltage on the DTC terminals (pin 6) is lower than the triangular-wave output voltage from the oscillator, the output transistor turns off. The dead time calculation formula assuming that triangular-wave amplitude 0.4 V and triangular-wave minimum voltage 1.4 V is given below. Vdt - 1.0 V x 100 [%] Duty (ON) MAX = : 0.4 When you do not use these DTC terminals, connect them to VREF terminal. * When using DTC to set dead time
16 VREF Ra 6 Vdt Rb DTC
* When not using DTC to set dead time
16 VREF
6
DTC
20
1. Step-down scheme
7 8 CB2 Error Amp1
-
CB1 1000 pF VO (3.3 V)
18 k OUT 9 Q4 10 OUT 22 F Q6 11 Q5 (0.5 V) VE U1FWJ44N Soft Start - Comp.
- + +
FB PWM Comp. OFF current setting block VCC 2SB1121S 22 H
s APPLICATION EXAMPLE
5 0.047 F 4 -IN 3 +IN
+ + + + -
15 k
DTC
6 47
10 k
CS 1 A
15 22 F 4.7 F
VIN SCP Comp.
CS
13
Q1
0.1 F (0.9 V) SCP 1 A 1.4 V bias 1.0 V RS Latch UVLO Q2 Q3 2 RT 6.2 k 0.1 F Ref Power ON/OFF 1.5 V 14 16 12 GND CSCP VREF 15 bias 1.5 V
VCC CTL (note) Output ON/OFF signal ON : CTL = 5 V OFF : CTL = 0 V 2SB1121S: SANYO Electric Co., Ltd. UIFWJ44N: TOSHIBA CORPORATION
OSC
1
CT
1000 pF
MB3817
21
22
MB3817
2. Zeta scheme
7 8 CB2 Error Amp1
-
CB1 1000 pF VO (3.3 V)
18 k OUT 9 VCC 22 H OUT 22 F 47 11 Q5 (0.5 V) VE U1FWJ44N
- - + +
FB PWM Comp. OFF current setting block 10 Q6
2SB1121S 4.7 F 22 H
15 k
5 0.047 F 4 -IN 3 +IN
+ + + + -
DTC
6
10 k
15 22 F 4.7 F
CS 1 A
VIN Soft Start Comp. SCP Comp.
CS
13
0.1 F
Q1
(0.9 V) 1.5 V SCP 1 A 1.4 V bias 1.0 V RS Latch UVLO Q2 Q3 2 RT 6.2 k 0.1 F Ref Power ON/OFF 1.5 V bias
VCC CTL 15
OSC
1
CT
14 16 12 GND CSCP VREF
(note) Output ON/OFF signal ON : CTL = 5 V OFF : CTL = 0 V
1000 pF
2SB1121S: SANYO Electric Co., Ltd. UIFWJ44N: TOSHIBA CORPORATION
3. Flyback scheme
OUT 7 8 CB2 Error Amp.
-
CB1 CB 1000 pF 2SB1121S U1FWJ44N VO (5.0 V)
35 k
R1 PWM Comp. 9 Q4 10 CS 1 A Q6 11 VE Q5 D1 (0.5 V) OUT 22 F RE 16 22 F VCC OFF current setting block
FB
5
0.047 F
+ + + + -
-IN
+IN
4
3
15 k
R2
1.2 k DTC
22 F
6
13 k
VIN Q1
- + +
CS Soft Start - Comp. SCP Comp.
13
1 F
(0.9 V) 1.5 V SCP 1 A -1.4 V -1.0 V OSC UVLO Q2 Q3 RS Latch 2 CT 6.2 k RT 2.2 F bias
bias
VCC 15
Power Ref (1.5 V) ON/OFF
CTL 14 16 12 CSCP VREF GND (note) Output ON/OFF signal ON : CTL = 5 V OFF : CTL = 0 V 2SB1121S: SANYO Electric Co., Ltd. UIFWJ44N: TOSHIBA CORPORATION
1
1000 pF
MB3817
23
MB3817
s APPLICATION
1. Equivalent series resistance and stability of smoothing capacitor
The equivalent series resistance (ESR) of the smoothing capacitor in the DC/DC converter greatly affects the loop phase characteristic. A smoothing capacitor with a high ESR improves system stability because the phase is advanced into the highfrequency range of an ideal capacitor (see Fig. 34 and 35) . A smoothing capacitor with a low ESR reduces system stability. Use care when using low ESR electrolytic capacitors (OS-CONTM) and tantalum capacitors. Note : OS-CON is the trademark of Sanyo Electric Co.,Ltd.
Figure 33
DC/DC Converter Basic Circuit
Tr
L
RC VIN D C RL
Figure 34
Gain vs. Frequency
Figure 35
Phase vs. Frequency
20
0
Phase (deg)
Gain AV (dB)
0 -20 -40 -60 10
(2) -90
(2)
(1) : RC = 0 (2) : RC = 31 m 100
(1) 100 k
-180 10
(1) : RC = 0 (2) : RC = 31 m
(1)
1k 10 k Frequency f (Hz)
100
1k 10 k Frequency f (Hz)
100 k
24
MB3817
Reference data In an aluminum electrolytic smoothing capacitor (RC = 1.0 ) is replaced with a low ESR electrolytic capacitor : (OS-CONTM : RC = 0.2 ) , the phase margin is reduced by half (see Fig. 37 and 38) . : Figure 36 DC/DC Converter AV vs. characteristic Test Circuit
VOUT VO+
CNF AV vs. characteristic Between this point
-
-IN +IN R1 VIN R2
FB
+
VREF/2 Error Amp.
Figure 37
60 40 AV Gain AV (dB) 20
DC/DC Converter +5 V output Gain vs. Phase
VCC = 10 V RL = 25 CP = 0.1 F 62
180 Phase (deg) 90 0 -90 -180 100 k
VO+ AI Condenser + 220 F (16 V) - RC 1.0 : fOSC = 1 kHz
0 -20 -40 10
GND
100
1k Frequency f (Hz)
10 k
Figure 38
60 AV 40 Gain AV (dB) 20 0 -20 -40 10
DC/DC Converter +5 V output Gain vs. Phase
VCC = 10 V RL = 25 CP = 0.1 F 27
180 Phase (deg) 90 0 -90 -180 100 k + -
VO+ OS-CON TM 22 F (16 V) RC 0.2 : fOSC = 1 kHz
GND
100
1k Frequency f (Hz)
10 k
25
MB3817
s NOTES ON USE
* Take account of common impedance when designing the earth line on a printed wiring board. * Take measures against static electricity. - For semiconductors, use antistatic or conductive containers. - When storing or carrying a printed circuit board after chip mounting, put it in a conductive bag or container. - The work table, tools and measuring instruments must be grounded. - The worker must put on a grounding device containing 250 k to 1 M resistors in series. * Do not apply a negative voltage - Applying a negative voltage of -0.3 V or less to an LSI may generate a parasitic transistor, resulting in malfunction.
s ORDERING INFORMATION
Part number MB3817PFV Package 16-pin Plastic SSOP (FPT-16P-M05) Remarks
26
MB3817
s PACKAGE DIMENSION
16-pin Plastic SSOP (FPT-16P-M05) Note 1) *1 : Resin protrusion. (Each side : +0.15 (.006) Max) . Note 2) *2 : These dimensions do not include resin protrusion. Note 3) Pins width and pins thickness include plating thickness. Note 4) Pins width do not include tie bar cutting remainder.
0.170.03 (.007.001)
9
*1 5.000.10(.197.004)
16
INDEX
*2 4.400.10 6.400.20 (.173.004) (.252.008)
Details of "A" part 1.25 -0.10 .049 -.004 LEAD No.
1 8
+0.20 +.008
(Mounting height)
0.65(.026)
"A" 0.240.08 (.009.003) 0.13(.005)
M
0~8 0.100.10 (Stand off) (.004.004) 0.25(.010)
0.10(.004)
0.500.20 (.020.008) 0.600.15 (.024.006)
C
2003 FUJITSU LIMITED F16013S-c-4-6
Dimensions in mm (inches) Note : The values in parentheses are reference values.
27
MB3817
FUJITSU LIMITED
All Rights Reserved. The contents of this document are subject to change without notice. Customers are advised to consult with FUJITSU sales representatives before ordering. The information, such as descriptions of function and application circuit examples, in this document are presented solely for the purpose of reference to show examples of operations and uses of Fujitsu semiconductor device; Fujitsu does not warrant proper operation of the device with respect to use based on such information. When you develop equipment incorporating the device based on such information, you must assume any responsibility arising out of such use of the information. Fujitsu assumes no liability for any damages whatsoever arising out of the use of the information. Any information in this document, including descriptions of function and schematic diagrams, shall not be construed as license of the use or exercise of any intellectual property right, such as patent right or copyright, or any other right of Fujitsu or any third party or does Fujitsu warrant non-infringement of any third-party's intellectual property right or other right by using such information. Fujitsu assumes no liability for any infringement of the intellectual property rights or other rights of third parties which would result from the use of information contained herein. The products described in this document are designed, developed and manufactured as contemplated for general use, including without limitation, ordinary industrial use, general office use, personal use, and household use, but are not designed, developed and manufactured as contemplated (1) for use accompanying fatal risks or dangers that, unless extremely high safety is secured, could have a serious effect to the public, and could lead directly to death, personal injury, severe physical damage or other loss (i.e., nuclear reaction control in nuclear facility, aircraft flight control, air traffic control, mass transport control, medical life support system, missile launch control in weapon system), or (2) for use requiring extremely high reliability (i.e., submersible repeater and artificial satellite). Please note that Fujitsu will not be liable against you and/or any third party for any claims or damages arising in connection with above-mentioned uses of the products. Any semiconductor devices have an inherent chance of failure. You must protect against injury, damage or loss from such failures by incorporating safety design measures into your facility and equipment such as redundancy, fire protection, and prevention of over-current levels and other abnormal operating conditions. If any products described in this document represent goods or technologies subject to certain restrictions on export under the Foreign Exchange and Foreign Trade Law of Japan, the prior authorization by Japanese government will be required for export of those products from Japan.
F0308 (c) FUJITSU LIMITED Printed in Japan

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