MIC2951-4.8BM Micrel Semiconductor, MIC2951-4.8BM Datasheet - Page 14

• Manufacturer Part Number: MIC2951-4.8BM
• Description: 150mA Low-Dropout Voltage Regulator
• Manufacturer: Micrel Semiconductor

Schematic Diagram
MIC2950/2951
For values shown, Regulator shuts down when V
* Sets disconnect voltage
** Sets disconnect hysteresis
LM34 for 125 F Shutdown
LM35 for 125 C Shutdown
AUX. SHUTDOWN
ON
+
FOR 5.5V
SENSOR
400k *
TEMP.
6V
SEALED
LEAD-
ACID
BATTERY
SOURCE
50 k
10 k
Q42
Q40
INPUT
R30
30
k
Q6
LM34 OR
OFF
50 k
20 k
Q41
LM35
R2
R1
10
Q1
Q3
–
+
120k
FB
3
50 k
R3
R11
18
k
ERROR
SD
180
IN
R5
k
System Overtemperature Protection Circuit
C1
20
pF
LM385
GND
Q13
13 k
R4
140
R6
k
MIC2951
4
+V IN
Q4
Q38
+V IN
–
Q12
1.5k **
100k
Q39
Q2
IN
Q5
31.4 k
27.8 k
Q37
8
ERROR
20.6
< 5.5 V and turns on again at 6.0 V. Current drain in disconnected mode is 150 A.
R11
R8
R9
Q15A
k
FB
Low-Battery Disconnect
R26
60 k
V
7
Q7
Q11
Q36
OUT
8.2k
R10
150
k
1N457
Q8
5
1
R25
2.8 k
Q9
3
Q34
3-62
SD
10k
R12
5 PRE-SHUTDOWN FLAG
110
k
Q20
OVER TEMPERATURE
(V+ GOES OFF WHEN
EXTERNAL CIRCUIT
PROTECTED FROM
Q18
R13
Q16
100
GND
MIC2951
k
+V IN
R22
150 k
GND
TEMP.> 125 )
Q15B
Q17
8
4
R14
350
k
C2
40 pF
SENSE
V
Q30
Q19
DENOTES CONNECTION ON MIC2950 ONLY
Q14
OUT
Q31
Q21
12 k
Q29
FEEDBACK
R17
1
2
R24
50 k
Q28
1 F
Q22
R15
100 k
R16
30 k
Q25
OR
R23 60 k
R21 8
R18
20k
+
Q26
10
R17
100 x
Q23
SHDN
RELAY
R27
182 k
R28
60 k
Q24
5V TAP
SENSE
OUT
February 1999
Micrel