View LT1309_341214.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

Final Electrical Specifications
LT1309 500kHz Micropower DC/DC Converter for Flash Memory
May 1995
FEATURES
s s s s s s s s s
DESCRIPTIO
s
60mA Output Current at 12V from 3V or 5V Supply Shutdown to 9A VPP VALID Comparator Up to 85% Efficiency Switching Frequency: 650kHz (Typical) Quiescent Current: 500A Low VCESAT Switch: 300mV at 0.5A (Typical) Soft Start Reduces Supply Current Transients Uses Low Value, Small Size, Surface Mount Inductors Available in 8-Lead SO Package
APPLICATI
s s s s s s
S
Flash Memory VPP Generators Type II and III PCMCIA Card DC/DC Converters 3V to 12V, 5V to 12V Converters Portable Computers and Instruments Cellular Telephones DC/DC Converter Module Replacements
The LT (R) 1309 is a 500kHz micropower DC/DC converter for Flash Memory. The regulator features Burst ModeTM operation with a 0.5A, 300mV switch, enabling 85% efficiency at the fixed 12V output. High frequency operation permits the use of small value, and therefore small size, surface mount inductors and capacitors. The LT1309 comes in an 8-lead SO package allowing extremely compact PC board layouts. These features make the device attractive for PCMCIA cards, cellular phones and other applications where PC board space is limited. Quiescent current is 650A decreasing to 9A when the part shuts down. The device includes a Soft Start feature which limits supply current transients during turn-on. The LT1309 contains a VPP VALID comparator with a logic output that goes low when the output voltage is ready to program 12V Flash Memory. This comparator simplifies the interface to external control logic.
, LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a trademark of Linear Technology Corporation.
TYPICAL APPLICATI
VIN 3.3V TO 5V VIN VPP VALID ON/OFF
12V, 60mA Flash Memory Programming Supply
L1* 10H D1
86
VPP 12V, 60mA
84
VSW
82
EFFICIENCY (%)
+
4.7F
VPP VALID SENSE LT1309 SOFT ON/OFF START PGND GND
80 78 76 74 VIN = 3.3V
1F** 1M 0.1F
* MURATA ERIE LQH3C100K0YM00 ** CERAMIC MOTOROLA MBR0530
72
LT1309 * TA01
70 1 10 LOAD CURRENT (mA) 100
LT1309 * TA02
Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
U
12V Output Efficiency
VIN = 5V
UO
UO
1
LT1309 ABSOLUTE AXI U RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW SOFT START 1 VCC 2 PGND 3 VSW 4 8 7 6 5 ON/OFF SENSE VPP VALID GND
VCC Voltage ............................................................... 7V VSW Voltage ............................................................ 20V VSENSE Voltage ....................................................... 20V VON/OFF Voltage......................................................... 7V VSEL Voltage ............................................................. 7V ILIM Voltage .............................................................. 7V Maximum Power Dissipation ............................ 500mW Operating Temperature Range ..................... 0C to 70C Storage Temperature Range ................. - 65C to 150C Lead Temperature (Soldering, 10 sec).................. 300C
ORDER PART NUMBER LT1309CS8 S8 PART MARKING 1309
S8 PACKAGE 8-LEAD PLASTIC SO
TJMAX = 150C, JA = 150C/W
Consult factory for Industrial and Military grade parts.
ELECTRICAL CHARACTERISTICS
SYMBOL IQ PARAMETER Quiescent Current Quiescent Current, Shutdown Input Voltage Range Output Sense Voltage Output Referred Comparator Hysteresis fOSC DC tON VCESAT Oscillator Frequency Maximum Duty Cycle Switch On Time Reference Line Regulation Switch Saturation Voltage Switch Leakage Current Switch Current Limit Soft Start Current ON/OFF Input Voltage Low ON/OFF Input Voltage High ON/OFF Bias Current
TA = 25C, VCC = 5V, VON/OFF = 3V, unless otherwise noted.
MIN TYP 650 9 2
q
CONDITIONS VSENSE = 12V VON/OFF = 0.2V
MAX 900 15 6 12.6 700 92 0.15 350 10 900 950 120 0.8
UNITS A A V V mV kHz % s %/V mV A mA mA A V V A A A A A V V V
11.5 400
12 35 500 85 1.7 0.06 230 0.1
Current Limit Not Asserted
q
80
2V < VIN < 6V ISW = 0.5A VSW = 12V, Switch Off VIN = 5V, Soft Start Floating VIN = 3V, Soft Start Floating Soft Start Grounded 1.6 VON/OFF = 5V VON/OFF = 3V VON/OFF = 0V VON/OFF = 0.2V 450 500
600 650 80
16.0 8.0 0.1 50.0 0.1
q
24.0 14.0 1.0 90 1 12 0.3
Sense Pin Input Current VPP VALID Threshold VPP VALID Output Voltage Low VPP VALID Output Voltage High VSENSE Rising (High to Low Transition) ISINK = 100A ISOURCE = 2.5A 4 11.4
0.13 4.5
The q denotes specifications which apply over the full operating temperature range.
2
U
W
U
U
WW
W
LT1309 TYPICAL PERFORMANCE CHARACTERISTICS
Sense Voltage
12.20 12.15
800
SUPPLY CURRENT (A)
SENSE VOLTAGE (V)
12.10 12.05 12.00 11.95 11.90 11.85 11.80 -50 -25 50 25 TEMPERATURE (C) 0 75 100
Supply Current In Shutdown
14 12 10 8 6 4 2 0 -50 VCC = 3V VCC = 5V 95
MAXIMUM DUTY CYCLE (%)
SUPPLY CURRENT (A)
-25
50 25 0 TEMPERATURE (C)
Start-Up Waveforms, ILOAD = 1mA
12V VOUT 2V/DIV VPP VALID 10V/DIV VON/OFF 10V/DIV 50s/DIV
LT1309 * TPC05
UW
Supply Current
700
VCC = 5V VCC = 3V
600
500
400
300 -50
-25
0 25 50 TEMPERATURE (C)
75
100
LT1309 * TPC01
LT1309 * TPC02
Maximum Duty Cycle
90
85
80
75
75
100
70 -50
-25
0 25 50 TEMPERATURE (C)
75
100
LT1309 * TPC03
LT1309 * TPC04
Start-Up Waveforms, ILOAD = 10mA
VOUT 5V/DIV 12V OUTPUT 1V/DIV AC COUPLED ILOAD 60mA 10mA
Load Transient Response, COUT = 1F
IL 500mA/DIV VON/OFF 10V/DIV 50s/DIV
LT1309 * TPC06
50s/DIV
LT1309 * TPC07
3
LT1309
PI FU CTIO S
SOFT START (Pin 1): A 0.1F/1M parallel RC from this pin to GND provides a Soft Start function upon device turn-on. Initially about 80A will flow from the pin into the capacitor. When the voltage at the pin reaches approximately 0.4V, current ceases flowing out of the pin. VCC (Pin 2): Input Supply. Both pins should be tied together. At least 1F input bypass capacitance is required. More capacitance reduces ringing on the supply line. PGND (Pin 3): Power Ground. Connect to ground plane. VSW (Pin 4): Collector of Power Switch. High dV/dt present on this pin. To minimize radiated noise keep layout short and direct. GND (Pin 5): Signal Ground. Connect to ground plane. VPP VALID (Pin 6): This pin provides a logic signal indicating that output voltage is greater than 11.4V. Active low with internal 200k pull-up resistor. SENSE (Pin 7): Output Sense Pin. This pin connects to a resistive divider that sets the output voltage. In shutdown, the resistor string is disconnected and current into this pin reduces to < 1A. ON/OFF (Pin 8): Shutdown Control. When pulled below 1.5V, this pin disables the LT1309 and reduces supply current to 9A. All circuitry is disabled in shutdown. The part is enabled when ON/OFF is greater than 1.5V.
BLOCK DIAGRA
SENSE 7
864k
4k OFF C1 500kHz OSCILLATOR
VREF 1.24V
RELATED PARTS
PART NUMBER
LT1106 LT1109-12 LT1109A-12 LTC 1262 LT1303
(R)
DESCRIPTION
Micropower Step-Up DC/DC Converter, 12V at 60mA Micropower Step-Up DC/DC Converter, 12V at 60mA Micropower Step-Up DC/DC Converter, 12V at 120mA Inductorless Flash Memory Programming Supply, 12V at 30mA Micropower High Efficiency DC/DC Converter with Low-Battery Detector
4
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7487
(408) 432-1900 q FAX: (408) 434-0507 q TELEX: 499-3977
+
100k
-
W
U
U
U
ON/OFF 8 POWER ON VREF VCC 200k C2 6 VPP VALID C3 36mV VCC 2
+ +- -
Q3 1 SOFT START Q2 1x R2 700 R1 3
+ -
BIAS SW 4 Q1 50x
5 GND
3 PGND
LT1309 * BD
COMMENTS
Thin TSSOP Package for Type I PCMCIA Card Flash Memory VPP Generator, Adjustable Also VPP Generator, Adjustable Also Switched Capacitor Converter, No Inductor Adjustable and Fixed 5V, IOUT up to 200mA
LT/GP 0695 6K * PRINTED IN THE USA
(c) LINEAR TECHNOLOGY CORPORATION 1995

▲Up To Search▲

Price & Availability of LT1309

	To Download LT1309 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .