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