Package Pin Description: continued
PIN SYMBOL FUNCTION
PACKAGE PIN #
16L SO Narrow & PDIP
11
PGnd
High current ground for the IC. The MOSFET driver is referenced to
this pin. Input capacitor ground and the anode of the Schottky diode
should be tied to this pin.
12
13
14
15
NC
VCC1
LGnd
COMP
No connection.
Input power for the IC.
Signal ground for the IC. All control circuits are referenced to this pin.
Error amplifier compensation pin. A capacitor to ground should be
provided externally to compensate the amplifier.
16
VFB
Error amplifier DC feedback input. This is the master voltage feedback
which sets the output voltage. This pin can be connected directly to the
output or a remote sense trace.
Block Diagram
V
CC2
VCC1 Monitor
Comparator
V
CC1
-
V
GATE
5V
SS Low
+
Comparator
-
FAULT
FAULT
3.90V
3.85V
R
S
Q
Q
+
PGnd
60µA
0.7V
FAULT
SS
Latch
SS High
Comparator
+
-
2µA
V
V
ID0
ID1
2.5V
Error
5 BIT
DAC
Amplifier
+
-
V
V
V
ID2
ID3
PWM
Comparator
-
ID4
GATE = ON
GATE = OFF
R
S
Q
Q
Maximum
On-Time
Timeout
+
Slow Feedback
Fast Feedback
V
FB
PWM
Latch
C
Normal
Off-Time
Timeout
COMP
OFF
One Shot
R
C
OFF
Extended
Off-Time
Timeout
V
Off-Time
Timeout
FFB
-
S
Q
+
V
Low
FFB
LGnd
Comparator
1V
PWM
Time Out
Timer
COMP
Edge Triggered
(30µs)
5
CHERRY [ CHERRY SEMICONDUCTOR CORPORATION ]
