L4978

Output Power :
Packaging : Tube
Output Current : 2 A
Mounting Style : Through Hole
Package / Case : PDIP-8
Operating Temperature Range : - 40 C to + 150 C
Input Voltage : 8 V to 55 V
Switching Frequency : 90 KHz to 110 KHz
Output Voltage : 50 V


Features:

·UP TO 2A STEP DOWN CONVERTER
·OPERATING INPUT VOLTAGE FROM 8V TO 55V
·PRECISE 3.3V (±1%) INTERNAL REFERENCE VOLTAGE
·OUTPUT VOLTAGE ADJUSTABLE FROM 3.3V TO 50V
·SWITCHING FREQUENCY ADJUSTABLE UP TO 500KHz
·VOLTAGEFEEDFORWARD
·ZERO LOAD CURRENT OPERATION
·INTERNAL CURRENT LIMITING (PULSE-BYPULSE AND HICCUPMODE)
·INHIBIT FOR ZERO CURRENT CONSUMPTION
·PROTECTION AGAINST FEEDBACK DISCONNECTION
·THERMAL SHUTDOWN
·SOFT START FUNCTION


Pinout




Specifications

Symbol		Parameter		Value	Unit
Minidip	SO16
V5	V11	Input voltage		58	V
V4	V5,V6	Output DC voltage Output peak voltage at t = 0.1s f=200KHz		-1 -5	V V
I4	I5,I6	Maximum output current		int. limit.
V6-V5	V12-V11			14	V
V6	V12	Bootstrap voltage		70	V
V7	V13	Analogs input voltage (VCC = 24V)		12	V
V2	V3	Analogs input voltage (VCC = 24V)		13	V
V8	V14	(VCC = 20V)		6 -0.3	V V
Ptot		Power dissipation a Tamb 60°C	Minidip	1	W
			SO16	0.8	W
Tj,Tstg		Junction and storage temperature		-40to150	°C

Description

The L4978 is a step down monolithic power switching regulator delivering 2A at a voltage between 3.3V and 50V (selected by a simple external divider). Realized in BCD mixed technology,the device uses an internal power D-MOS transistor (with a typical Rdson of 0.25W) to obtain very high efficency and high switching speed.

A switching frequency up to 500KHz is achievable (the maximum power dissipation of the packages must be observed).

A wide input voltage range between 8V to 55V and output voltages regulated from 3.3V to 50V cover the majority of today's applications.

Features of this new generations of DC-DC converter L4978  include pulse-by-pulse current limit, hiccup mode for short circuit protection, voltage feedforward regulation, soft-start, protection against feedback loop disconnection, inhibit for zero current consumption and thermal shutdown.

L4978 is available in plastic dual in line,MINIDIP 8 for standard assembly, and SO16W for SMD assembly.

Parameters:

Technical/Catalog Information	L4978
Vendor	STMicroelectronics
Category	Integrated Circuits (ICs)
Type	Step-Down (Buck)
Number of Outputs	1
Voltage - Input	8 ~ 55 V
Voltage - Output	3.3 ~ 50 V
Current - Output	2A
Power - Output	1W
Package / Case	8-DIP (300 mil)
Packaging	Tube
Internal Switch(s)	Yes
Synchronous	No
Rds (On)	250 mOhm
Operating Temperature	-40°C ~ 150°C
Frequency - Switching	100kHz ~ 300kHz
Lead Free Status	Lead Free
RoHS Status	RoHS Compliant
Other Names	L4978 L4978 497 6701 5 ND 49767015ND 497-6701-5