MICROELECTRONICS
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Power Management
GM7230
3A STEP-DOWN VOLTAGE REGULATOR
Description
GM7230 of regulators provides all the active functions for a
step-down (buck) switching regulator, and drives 3A load
with excellent line and load regulation. GM7230's is avail-
able in fixed output voltages of 3.3V, 5V, 12V, and a versa-
tile
Adjustable output version.
These regulators are simple to use and require a minimum
number of external components. Features include internal
frequency compensation and a fixed-frequency oscillator.
The GM7230 is high-efficiency replacements for popular
three-terminal linear regulators, and is requiring a smaller
heatsink or even no heatsink.
GM7230 performs well with standard inductors from sev-
eral manufacturers, and simplifying the design of switch-
mode power supplies. GM7230 guarantees ±4% tolerance
on output voltage within specified input voltages and out-
put load conditions, and ±15% on the oscillator frequency.
External shutdown is included with 80 µA (typical) standby
current. The output switch has cycle-by-cycle current limit-
ing as well as thermal shutdown for full protection under
fault conditions.
GM7230 operates at a switching frequency of 150 kHz thus al-
lowing smaller sized filter components than what would be
needed with lower frequency switching regulators. Available in a
standard 5-lead TO-220 package with several different
lead bend options, and a 5-lead TO-263 surface mount
package.
Features
3.3V, 5V, 12V and Adjustable output versions
Adjustable version output voltage range 1.23V
to 37V
4% max over line and load conditions
3A output current
Input voltage range up to 40V
Requires only 4 external components
High efficiency
TTL shutdown capability, low power standby
mode
Low power standby mode, IQ typically 80 UA
Thermal shutdown, current limit protection
Uses standard inductors
150 kHz fixed frequency internal oscillator
Application
Pre-regulator for linear regulators
High-efficiency step-down buck regulator
On-card/board switching regulators
Positive to negative converter (buck-boost)
TYPICAL APPLICATIONS
12V
Unregulated
DC Input
+V
IN
1
+ C
IN
GM7230
5.0
L1
68 µH
+
C
OUT
220 µF
5
680 µF
ON / OFF
3
GND
5.0V
Regulated
Output
3A Load
D1
1N5824
www.gammamicro.com
GM7230
V0.11
1
Feedback
4
Output
2
GAMMA [ GAMMA MICROELECTRONICS INC. ]
