
ADP1173
–3–
REV. 0
ABSOLUTE MAXIMUM RATINGS*
Supply Voltage (V
IN
) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 V
SW1 Pin Voltage (V
SW1
) . . . . . . . . . . . . . . . . . . . . . . . . . 50 V
SW2 Pin Voltage (V
SW2
) . . . . . . . . . . . . . . . . . . –0.5 V to V
IN
Feedback Pin Voltage (ADP1173) . . . . . . . . . . . . . . . . . . . 5 V
Sense Pin Voltage (ADP1173, –3.3, –5, –12) . . . . . . . . . 36 V
Maximum Power Dissipation . . . . . . . . . . . . . . . . . . 500 mW
Maximum Switch Current . . . . . . . . . . . . . . . . . . . . . . . .1.5 A
Operating Temperature Range . . . . . . . . . . . . . 0
°
C to +70
°
C
Storage Temperature Range . . . . . . . . . . . . . –65
°
C to 150
°
C
Lead Temperature, (Soldering, 10 sec) . . . . . . . . . . . .+300
°
C
*Stresses above those listed under Absolute Maximum Ratings may cause perma-
nent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those listed in the operational
sections of this specification is not implied. Exposure to absolute maximum
ratings for extended periods of time may affect device reliability.
ORDERING GUIDE
Output
Voltage
Package
Options*
Model
ADP1173AN
ADP1173AR
ADP1173AN-3.3
ADP1173AR-3.3
ADP1173AN-5
ADP1173AR-5
ADP1173AN-12
ADP1173AR-12
ADJ
ADJ
3.3 V
3.3 V
5 V
5 V
12 V
12 V
N-8
SO-8
N-8
SO-8
N-8
SO-8
N-8
SO-8
*N = Plastic DIP, SO = Small Outline Package.
I
LIM
ADP1173
SET
V
IN
SW1
FB
SW2
4
GND
5
1
2
3
8
7
AO
6
+
L1*
100μH
470μF
75k
56
*L1 = COILTRONICS CTX100-4
4X NICAD
OR
ALKALINE
CELLS
240
470μF
+
470k
24k
IRF7203
+
470μF
+5V
OUTPUT
AT 100mA
Figure 1. Step-Up or Step-Down Converter
PIN CONFIGURATIONS
N-8
8-Lead Plastic DIP
SO-8
8-Lead Plastic SO
WARNING!
ESD SENSITIVE DEVICE
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the ADP1173 features proprietary ESD protection circuitry, permanent damage may
occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD
precautions are recommended to avoid performance degradation or loss of functionality.
AO
I
LIM
SW1
GND
V
IN
SW2
*FIXED VERSIONS
1
2
3
4
8
7
6
5
ADP1173
TOP VIEW
(Not to Scale)
FB (SENSE)*
SET
AO
I
LIM
SW1
GND
V
IN
SW2
*FIXED VERSIONS
1
2
3
4
8
7
6
5
ADP1173
(TOP VIEW
FB (SENSE)*
SET
PIN FUNCTION DESCRIPTIONS
Mnemonic
Function
I
LIM
For normal conditions this pin is connected to
V
IN
. When lower current is required, a resistor
should be connected between I
LIM
and V
IN.
Limiting the switch current to 400 mA is
achieved by connecting a 220
resistor.
Input Voltage.
Collector Node of Power Transistor.
For step-down configuration, connect to V
IN
;
for step-up configuration, connect to an
inductor/diode.
Emitter Node of Power Transistor. For step-
down configuration, connect to inductor/
diode; for step-up configuration, connect to
ground. Do not allow this pin to drop more
than a diode drop below ground.
Ground.
Auxiliary Gain (GB) Output. The open
collector can sink 100
μ
A.
Gain Amplifier Input. The amplifier has
positive input connected to the SET pin and
negative input is connected to 1.245 V
reference.
On the ADP1173 (adjustable) version this pin
is connected to the comparator input. On the
ADP1173-3.3, ADP1173-5 and ADP1173-12,
the pin goes directly to the internal application
resistor that sets the output voltage.
V
IN
SW1
SW2
GND
AO
SET
FB/SENSE