L4974A

Output Power :
Packaging : Tube
Mounting Style : Through Hole
Output Voltage : 40 V
Operating Temperature Range : - 40 C to + 150 C
Input Voltage : 15 V to 50 V
Output Current : 3.5 A
Switching Frequency : 90 KHz to 110 KHz
Package / Case : PDIP-20


Features:

·3.5AOUTPUT CURRENT .
·5.1V TO 40VOUTPUT VOLTAGERANGE
·0 TO 90%DUTY CYCLE RANGE .
·INTERNAL FEED-FORWARD LINEREG.
·INTERNALCURRENT LIMITING
·PRECISE5.1V ± 2% ON CHIP REFERENCE
·RESET AND POWER FAIL FUNCTIONS .
·INPUT/OUTPUT SYNC PIN
·UNDER VOLTAGE LOCK OUT WITH HYS.
·TERETIC TURN-ON PWM LATCH FOR SINGLE
·PULSE PER PE.RIOD
·VERY HIGH EFFICIENCY .
·SWITCHING FREQUENCY UP TO 200KHz
·THERMAL SHUTDOWN
·CONTINUOUS MODE OPERATION

 

Pinout




Specifications

Symbol	Parameter	Value	Unit
V11	Input Voltage	55	V
V11	Input Operating Voltage	50	V
V20	Output DC Voltage Output Peak Voltage at t = 0.1s f =200khz	-1 -5	V V
I20	Maximum Output Current	Internally Limited
VI	Boostrap Voltage Boostrap Operating Voltage	65 V11+15	V V
V4,V8	Input Voltage at Pins 4, 12	12	V
V3	Reset Output Voltage	50	V
I3	Reset Output Sink Current	50	mA
V2,V7,V9,V10	Input Voltage at Pin 2, 7, 9, 10	7	V
I2	Reset Delay Sink Current	30	mA
I7	Error Amplifier Output Sink Current	1	A
I8	Soft Start Sink Current	30	mA
Ptot	Total Power Dissipation at TPINS 90°Cat Tamb= 70°C (No copper area on PCB)	5 1.3	W W
TJ,TSTG	Junction and Storage Temperature	-40to150	°C

Description

The L4974Aisa stepdownmonolithicpowerswitching regulator delivering 3.5A at a voltage variable from 5.1 to 40V.

Realized with BCD mixed technology, the device uses a DMOS output transistor to obtain very high efficiencyand very fast switching times. Featuresof the L4974A include reset and power fail for microprocessors,feed forward line regulation, soft start,limiting current and thermal protection. L4974A  is mountedin a Powerdip16 + 2 + 2 plasticpackage and requires few external components. Efficient operation at switching frequencies up to 200KHz allowsreductionin the size andcost of external filter component.

Parameters:

Technical/Catalog Information	L4974A
Vendor	STMicroelectronics
Category	Integrated Circuits (ICs)
Type	Step-Down (Buck)
Number of Outputs	1
Voltage - Input	15 ~ 50 V
Voltage - Output	5.1 ~ 40 V
Current - Output	3.5A
Power - Output	1.3W
Package / Case	20-DIP
Packaging	Tube
Internal Switch(s)	Yes
Synchronous	Yes
Rds (On)	-
Operating Temperature	0°C ~ 125°C
Frequency - Switching	100kHz
Lead Free Status	Lead Free
RoHS Status	RoHS Compliant
Other Names	L4974A L4974A 497 6699 5 ND 49766995ND 497-6699-5