MIC2950 Datasheet, PDF (14/14 Pages) Micrel Semiconductor – 150mA Low-Dropout Voltage Regulator

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