MIC38HC42/3/4/5
Micrel, Inc.
Pin Configuration
MIC38HC4x-1
COMP 1
NC 2
FB 3
14 VREF
13 NC
12 VDD
11 VD
10 OUT
9 AGND
8 PGND
MIC38HC4x
COMP 1
FB 2
ISNS 3
RT/CT 4
8
7
6
5
VREF
VDD
OUT
GND
NC 4
ISNS 5
NC 6
RT/CT 7
8-Pin DIP (N)
8-Lead SOIC (M)
14-Pin DIP (-1BN)
14-Lead SOIC (-1BM)
Pin Description
Pin Number
N, M, MM
1
Pin Number
-1BN, -1BM
1
2
2
3
4
3
5
6
4
5
8
9
6
10
11
7
12
13
8
14
7
Pin Name
COMP
NC
FB
NC
ISNS
NC
RT/CT
GND
PGND
AGND
OUT
VD
VDD
NC
VREF
Pin Function
Compensation: Connect external compensation network to modify the error
amplifier output.
Not internally connected.
Feedback (Input): Error amplifier input. Feedback is 2.5V at desired output
voltage.
Not internally connected.
Current Sense (Input): Current sense comparator input. Connect to current
sensing resistor or current transformer.
Not internally connected.
Timing Resistor/Timing Capacitor: Connect external RC network to select
switching frequency.
Ground: Combined analog and power ground.
Power Ground: N-channel driver transistor ground.
Analog Ground: Controller circuitry ground.
Power Output: Totem-pole output.
Power Supply (Input): P-channel driver transistor supply input. Return to
power ground (PGND).
Analog Supply (Input): Controller circuitry supply input. Return to analog
ground (AGND).
Not internally connected.
5V Reference (Output): Connect external RC network.
April 2005
3
M9999-042205
MICREL [ MICREL SEMICONDUCTOR ]
