ML4821
PIN CONNECTION
ML4821
18-Pin DIP (P18)
I
LIM
IA OUT
IA–
IA+
I
SINE
EA OUT
EA–
V
RMS
SOFT START
1
2
3
4
5
6
7
8
9
18
17
16
15
14
13
12
11
10
ML4821
20-Pin SOIC (S20)
GND
C
T
V
REF
V
CC
OUT
PGND
R
T
OVP
SYNC
I
LIM
IA OUT
IA–
IA+
I
SINE
EA OUT
EA–
V
RMS
SOFT START
N/C
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
GND
C
T
V
REF
V
CC
OUT
PGND
R
T
OVP
SYNC
N/C
TOP VIEW
TOP VIEW
PIN DESCRIPTION
(Pin numbers in parentheses are for 20-pin packages)
PIN
NAME
FUNCTION
PIN
NAME
FUNCTION
1 (1)
2 (2)
3 (3)
4 (4)
I
LIM
Peak cycle-by-cycle current limit input
10 (12) SYNC
11 (13) OVP
Oscillator synchronization input
Inhibits output pulses when the
voltage at this pin exceeds 5V. Also,
when the voltage at this pin is less
than 0.7V, the IC goes into low current
shut-down mode.
Timing resistor for the oscillator
Return for the high current totem
pole output
High current totem pole output
Positive supply for the IC
Buffered output for the 5V voltage
reference
Timing capacitor for the oscillator.
Analog signal ground
IA OUT Output and compensation node of the
average current error amplifier
IA–
IA+
Inverting input of the average current
error amplifier
Non-Inverting input of the average
current error amplifier and output of
the gain modulator
Gain modulator input
12 (14) R
T
13 (15) PWR
GND
14 (16) OUT
15 (17) V
CC
16 (18) V
REF
17 (19) C
T
18 (20) GND
5 (5)
6 (6)
7 (7)
8 (8)
9 (9)
I
SINE
EA OUT Output of output voltage error
amplifier
INV
V
RMS
SOFT
START
Inverting input to error amplifier
Input for average line voltage
compensation
Normally connected to soft start
capacitor
2
Micro Linear
MICRO-LINEAR [ MICRO LINEAR CORPORATION ]
