L5993 Datasheet, PDF (1/22 Pages) STMicroelectronics – CONSTANT POWER CONTROLLER

®
L5993
CONSTANT POWER CONTROLLER
CURRENT-MODE CONTROL PWM
SWITCHING FREQUENCY UP TO 1MHz
LOW START-UP CURRENT (< 120µA)
CONSTANT OUTPUT POWER VS. SWITCH-
ING FREQUENCY
HIGH-CURRENT OUTPUT DRIVE SUITABLE
FOR POWER MOSFET (1A)
FULLY LATCHED PWM LOGIC WITH DOU-
BLE PULSE SUPPRESSION
PROGRAMMABLE DUTY CYCLE
100%AND 50% MAXIMUM DUTY CYCLE LIMIT
PROGRAMMABLE SOFT START
PRIMARY OVERCURRENT FAULT DETEC-
TION WITH RE-START DELAY
PWM UVLO WITH HYSTERESIS
IN/OUT SYNCHRONIZATION
LATCHED DISABLE
INTERNAL 100ns LEADING EDGE BLANK-
ING OF CURRENT SENSE
PACKAGE: DIP16 AND SO16N
DESCRIPTION
This primary controller I.C., developed in BCD60II
technology, has been designed to implement off
BLOCK DIAGRAM
MULTIPOWER BCD TECHNOLOGY
DIP16
SO16N
ORDERING NUMBERS: L5993 (DIP16)
L5993D (SO16)
line or DC-DC power supply applications using a
fixed frequency current mode control.
Based on a standard current mode PWM control-
ler this device includes some features such as
programmable soft start, IN/OUT synchronization,
disable (to be used for over voltage protection and
for power management), precise maximum Duty
Cycle Control, 100ns leading edge blanking on
current sense, pulse by pulse current limit, over-
current protection with soft start intervention and
”constant power” function for cotrolling throughput
power in multisync monitor SMPS.
RCT
DC
DIS
C-POWER
ISEN
SS
SYNC
1
DC-LIM
15
V_CC
8
2
TIMING
+
3
-
25V
+
T
15V/10V -
14
-
+
2.5V
DIS
+
16
-
BLANKING
SQ
R
PWM
OVER CURRENT
13
+
-
1.2V
FAULT
SOFT-START
VREF OK
CLK
DIS
7
2R
1V
R
Vref
PWM UVLO
VREF
4
9
13V
10
11
+
2.5V
E/A
5
-
V_C
OUT
PGND
VFB
12
SGND
6
COMP
D97IN765
July 1999
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