Datasheet

put filter; both the operating frequency modes
working with an average current mode PWM con-
troller, maintaining sinusoidal line current without
slope compensation.
Besides power MOSFET gate driver, precise volt-
age reference (externally available), error ampli-
fier, undervoltage lockout, current sense and the
soft start are included. To limit the number of the
external components, the device integrates pro-
tections as overvoltage and overcurrent. The
overcurrent level can be programmed using a
simple resistor for L4981A. For a better precision
and for L4981B an external divider must be used.
ABSOLUTE MAXIMUM RATINGS
Symbol Pin Parameter Value Unit
V
CC
19 Supply Voltage (I
CC
≤50mA) (*) selflimit V
I
GDRV
20 Gate driv. output peak current (t = 1µs) SINK 2 Α
. SOURCE 1.5 A
V
GDRV
Gate driv. output voltage t = 0.1µs-1V
Voltages at pins 3, 14, 7, 6, 12, 15 -0.3 to 9 V
V
VA-OUT
13 Error Amplifier Voltage -0.3 to 8.5 V
I
AC
4 AC Input Current 5 mA
Voltages at pin 8, 9 -0.5 to 7 V
V
CA-OUT
5 Current Amplifier Volt. (Isource = -20mA; Isink = 20mA) -0.3 to 8.5 V
V
ROSC
17 Voltage at pin 17 -0.3 to 3 V
11, 18 Voltage at pin 11, 18 -0.3 to 7 V
I
COSC
18 Input Sink Current 15 mA
I
FREQ-MOD
16 Frequency Modulation Sink Current (L4981B) 5 mA
V
SYNC
16 Sync. Voltage (L4981A) -0.3 to 7 V
V
IPK
2 Voltage at pin 2
Voltage at Pin 2 t = 1µs
-0.3 to 5.5
-2
V
V
P
tot
Power Dissipation at T
amb
= 70°C (DIP20) 1 W
Power Dissipation at T
amb
= 70°C (SO20) 0.6 W
T
op
Operating Ambient Temperature -40 to 125 °C
T
stg
StorageTemperature -55 to 150 °C
(*) Maximum package power dissipation limits must be observed.
PIN CONNECTIONS
(Top views)
L4981A
L4981B
L4981A - L4981B
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