AS998 Datasheet, PDF (1/6 Pages) List of Unclassifed Manufacturers – IC intended for use as a PWM controller

SEMICONDUCTOR
AS998/A
PWM Controller
Preliminary Specification
Features
Description
• Low start-up current 64 µA (Typ)
The AS998/AS998A is an IC intended for use as a PWM controller for
• Low running current 2 mA (Typ)
switch mode power supplies. The device is particularly suited as a pri-
mary side controller for adapter, printer, peripheral, mobile chargers and
• Low power light load mode
• Low power standby when OV is
activated
• Extended commercial operating
temperature range: 0 to 105°C
• On-board fixed frequency oscillator 100
kHz (Typ)
• Frequency randomizer to reduce EMC
emissions
• Dedicated OV shutdown pin
• On-board voltage ramp compensation
• On-board current sensing filtering
• Optional primary side regulation
desktop auxiliary power supplies. The AS998/AS998A is manufactured
in BICMOS technology and exhibits very low start-up and operating
power. This allows the device to be suitable in applications where strin-
gent standby or Blue Angel criteria are required.
Many of the external functions associated with PWM controllers have
Y been integrated into the AS998/AS998A allowing the external compo-
nent count to be significantly reduced. Features such as fixed internal
oscillator, internal ramp compensation and current filters all reduce the
external support components.
A ^{R The AS998/AS998A has a typical output rise and fall time of 250/210 ns.}
IN
Pin Configuration – Top View
M _{8L PDIP (8N)}
I _{OV 1}
Comp 2
L _{VFB 3}
E ^{ISENSE 4}
8 V_REG
7 V_CC
6 OUT
5 GND
OV
Comp
V_FB
I_SENSE
P ^{R Ordering Information}
AS998/A B 8D N
1
2
3
4
8L SOIC (8D)
8 V_REG
7 V_CC
6 OUT
5 GND
Circuit Type:
PWM Controller (Models AS998 & AS998A)
Temperature Range:
B = 0°C to 105°C
Packaging Option:
T = Tubes
N = Tape and Reel (13" Reel Dia.)
Package Type:
8D = 8 Pin, Plastic SOIC
8N = 8 Pin, Plastic DIP
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