2001 Fairchild Semiconductor Corporation
www.fairchildsemi.com
Rev. 1.0.1
Features
0.5A / 3.3V Output low dropout voltage regulator
Low dropout voltage (Max. 0.6V)
Over current protection, Thermal shutdown
SOA protection, Shortcircuit protection
Description
The KA78RM33 is a low-dropout voltage regulator suitable
for various electronic equipment. It provide constant voltage
power source with surface mount type package (D-PAK).
dropout voltage of KA78RM33 is below 0.6V in full rated
current(0.5A). This regulator has various function such as
over current protection, thermal shut down and SOA (Safe
operating Area) protection.
D-PAK
TO-220
1
1
1. Vin 2. GND 3. Vout
Internal Block Digram
3
1
Vin
3 Vout
GND
Q1
R1
R2
Current
Generator
Thermal
Shutdown
Protection
SOA
Protection
Short Circuit
Protection
Bandgap
Reference
Error
Amp.
Output
Drive
2
KA78RM33
Low Dropout Voltage Regulator
KA78RM33
2
Absolute Maximum Ratings
Electrical Characteristics
(Vin = 5V, I
O
= 0.25A, Ta = 25
C , unless otherwise specified
)
Parameter
Symbol
Value
Unit
Remark
Input Voltage
Vin
20
V
-
Output Current
I
O
0.5
-
Thermal Resistance Junction-Air
R
JA
110
C/W
No Heatsink
Power Dissipation
Pd
Interally limited
-
-
Junction Temperature
Tj
150
C
-
Operating Temperature
T
OPR
-25~ + 125
C
-
Parameter
Symbol
Conditions
Min.
Typ. Max.
Unit
Output Voltage
V
Out
I
O
=10mA
3.22
3.3
3.38
V
Load Regulation
Rl
Oad
5mA < I
O
< 0.5A
-
2
20
mV
Line Regulation
R
line
4.3V <Vin < 16V
-
2
20
mV
Ripple Rejection Ratio
RR
f=120Hz, Vin=5V 0.5Vrms
55
-
-
dB
Dropout Voltage
V
drop
I
O
=0.5A
-
-
0.6
V
Quiescent Current
q
I
O
= 0A
-
5
10
mA
Peak Current
I
PK
Vin = 5V
0.5
1
-
A
Output Noise Voltage
V
n
10Hz < f < 100KHz
-
50
-
uVrms
Temperature Coefficient of Output
Voltage
V
OUT
/
T
-25
C < Tj < 125
C
I
O
= 100mA
-
-0.2
-
mV/
C
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