GAMMA GM7230

GM7230
150KHz, 3A STEP DOWN VOLTAGE
SWITCHING REGULATORS
Description
Features
GM7230 series is designed to provide all the
active function for a step-down (buck) switching
regulator, and drives a maximum load current as
high as 3A line and load regulations. GM7230 is
available in fixed output voltages of 3.3V, 5V,
and a versatile Adjustable output version.
These regulators are simple to use and require
minimum number of external components. The
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 heat sink or even no need
heat sink.
GM7230 performs well with standard inductors
from most of manufacturers, and simplifying the
design of switch-mode power supplies. External
shutdown is included with 80 µA (typical) standby
current. The output switch has cycle-by-cycle
current limiting as well as thermal shutdown for
full protection under fault conditions.

3.3V, 5V, 12Vand Adjustable output
versions

Adjustable version output voltage range
1.23V to 37V

VOUT accuracy is to ± 2% under specified
input voltage the output load conditions

Input voltage range up to 40V

Requires only 4 external components with
High efficiency

TTL shutdown capability, low power
standby mode

Built-in thermal shutdown, current limit
protection

Uses standard inductors

150 kHz fixed frequency internal oscillator
GM7230 operates at a switching frequency of
150 kHz which allowing smaller size filter
components than what would be needed with
lower frequency switching regulators.
GM7230 series are available in a standard 5-lead
TO-220, TO220B and TO263 packages.
Application
Pre-regulator for linear regulators
On-card/board switching regulators
High-efficiency step-down buck regulator
Positive to negative converter (buck-boost)
LCD Monitors
Typical Application Circuits
GM7230-5.0
Feedback
L1
68μH
Output
CIN
680μF
4
1 VIN
GND
3
2
5V
regulated
output,
ON/OFF
5
D1
1N5824
COUT
220μF
www.gammamicro.com.tw
GM7230V2.02
Unregulated
DC Input
1
GM7230
150KHz, 3A STEP DOWN VOLTAGE
SWITCHING REGULATORS
Marking Information and Pin Configurations (Top View)
TO-220-5
TO-220B-5
TO-263-5
GM7230
VVAYWW
GM7230
VVAYWW
GM7230
VVAYWW
5. ON/OFF
4. Feedback
3. GND
2. Output
1. VIN
5. ON/OFF
4. Feedback
3. GND
2. Output
1. VIN
5. ON/OFF
4. Feedback
3. GND
2. Output
1. VIN
G: Green Product
VV: Voltage suffix (15 = 1.5V, 50 = 5.0V…A = Adj)
A: Assembly / Test site code
Y: Year
WW: Week
Marking Information and Pin Configurations – Green Products (Top View)
TO-220-5
TO-220B-5
TO-263-5
GM7230G
VVAYWW
GM7230G
VVAYWW
GM7230G
VVAYWW
GM7230V2.02
5. ON/OFF
4. Feedback
3. GND
2. Output
1. VIN
5. ON/OFF
4. Feedback
3. GND
2. Output
1. VIN
5. ON/OFF
4. Feedback
3. GND
2. Output
1. VIN
2
G: Green Product
VV: Voltage suffix (15 = 1.5V, 50 = 5.0V…A = Adj)
A: Assembly / Test site code
Y: Year
WW: Week
GM7230
150KHz, 3A STEP DOWN VOLTAGE
SWITCHING REGULATORS
Ordering Information – Pb Free Products
Ordering Number
Output Voltage
Package
Shipping
TO-263-5
50 Units / Tube
TO-263-5
800 Units / Reel
TO-220-5
50 Units / Tube
GM7230-ATB5BT
TO-220-5B
50 Units / Tube
GM7230-3.3TA5T
TO-263-5
50 Units / Tube
TO-263-5
800 Units / Reel
TO-220-5
50 Units / Tube
TO-220-5B
50 Units / Tube
TO-263-5
50 Units / Tube
TO-263-5
800 Units / Reel
GM7230-5.0TB5T
TO-220-5
50 Units / Tube
GM7230-12TB5BT
TO-220-5B
50 Units / Tube
TO-263-5
50 Units / Tube
TO-263-5
800 Units / Reel
TO-220-5
50 Units / Tube
TO-220-5B
50 Units / Tube
Package
Shipping
TO-263-5
50 Units / Tube
TO-263-5
800 Units / Reel
TO-220-5
50 Units / Tube
GM7230-ATB5BTG
TO-220-5B
50 Units / Tube
GM7230-3.3TA5TG
TO-263-5
50 Units / Tube
TO-263-5
800 Units / Reel
TO-220-5
50 Units / Tube
TO-220-5B
50 Units / Tube
TO-263-5
50 Units / Tube
TO-263-5
800 Units / Reel
GM7230-5.0TB5TG
TO-220-5
50 Units / Tube
GM7230-12TB5BTG
TO-220-5B
50 Units / Tube
TO-263-5
50 Units / Tube
TO-263-5
800 Units / Reel
TO-220-5
50 Units / Tube
TO-220-5B
50 Units / Tube
GM7230-ATA5T
GM7230-ATA5R
Adj
GM7230-ATB5T
GM7230-3.3TA5R
3.3
GM7230-3.3TB5T
GM7230-3.3TB5BT
GM7230-5.0TA5T
GM7230-5.0TA5R
5.0
GM7230-12TA5T
GM7230-12TA5R
12
GM7230-12TB5T
GM7230-12TB5BT
Ordering Information – Green Products
Ordering Number
Output Voltage
GM7230-ATA5TG
GM7230-ATA5RG
Adj
GM7230-ATB5TG
GM7230-3.3TA5RG
3.3
GM7230-3.3TB5TG
GM7230-3.3TB5BTG
GM7230-5.0TA5TG
GM7230-5.0TA5RG
GM7230-12TA5TG
GM7230-12TA5RG
12
GM7230-12TB5TG
GM7230-12TB5BTG
GM7230V2.02
5.0
3
GM7230
150KHz, 3A STEP DOWN VOLTAGE
SWITCHING REGULATORS
Absolute Maximum Ratings (Note 1)
Rating
Value
Unit
45
V
SD Pin Input Voltage / Feed Back Pin Voltage
-0.3 + VIN + 0.3
V
Output Voltage to Ground (Steady State)
-0.3 + VIN + 0.3
V
Internally Limited
-
36
℃/W
- 65 to 150
℃
+ 150
℃
Operating Temperature Range
- 40 to 125
℃
Minimum EDS Rating (Note 2)
2
kV
+ 260
℃
Maximum Supply Voltage
Power Dissipation
Thermal Resistance – Junction to Ambient (JA)
** 2 square inch of FR-4, double sided, 1oz. minimum copper weight, is
recommended
Storage Temperature Range
Maximum Junction Temperature
Lead Temperature (Soldering, 10 sec)
Block Diagram
SD
VIN
Current
Source
Bias
1.235V
Reference
2.5V
Reference
Start UP
220
COMP
Current
Limit
2.5V
COMP
FB
GM
R2
220mV
3A
Switch
AMP
COMP
Latch
Driver
R1 = 2.5K
Reset
GM7230V2.02
For 3.3V, R2 = 4.2K
For 5.0V, R2 = 7.6K
For Adj, R2 = 0 and R1 = OPEN
4
Freq. Shift
150KHz
OSC
Thermal
Limit
OUTPUT
GND
GM7230
150KHz, 3A STEP DOWN VOLTAGE
SWITCHING REGULATORS
Electrical Characteristics: GM7230-ADJ
(Specifications with standard type face are for T = 25°C, and those with bold face type apply over full Operating
Temperature rage)
Parameter
Condition
Output Voltage
4.5V  VIN  40V, 0.2A  ILOAD  3A,
VOUT = 3V
Efficiency
VIN =12V, ILOAD=2.0A, VOUT = 3V
Symbol
VOUT
Min
1.193
1.180
η
Typ
1.230
Max
1.267
1.280
73
Unit
V
%
Electrical Characteristics: GM7230-3.3
(Specifications with standard type face are for T = 25°C, and those with bold face type apply over full Operating
Temperature rage)
Parameter
Condition
Output Voltage
4.75V  VIN  40V, 0.2A  ILOAD  3A
Efficiency
VIN =12V, ILOAD=2.0A
Symbol
VOUT
Min
3.168
3.135
η
Typ
3.300
Max
3.432
3.465
73
Unit
V
%
Electrical Characteristics: GM7230-5.0
(Specifications with standard type face are for T = 25°C, and those with bold face type apply over full Operating
Temperature rage)
Parameter
Condition
Output Voltage
7V  VIN  40V, 0.2A  ILOAD  3A
Efficiency
VIN =12V, ILOAD=2.0A
Symbol
VOUT
Min
4.800
4.7500
η
Typ
5.000
Max
5.200
5.250
80
Unit
V
%
Electrical Characteristics: GM7230-12
(Specifications with standard type face are for T = 25°C, and those with bold face type apply over full Operating
Temperature rage)
Condition
Output Voltage
15V  VIN  40V, 0.5A  ILOAD  3A
Symbol
Min
Typ
11.52
Efficiency
VIN =15V, ILOAD=3.0A
VOUT
η
Max
Unit
12.48
12.00
11.40
V
12.60
88
%
GM7230V2.02
Parameter
5
GM7230
150KHz, 3A STEP DOWN VOLTAGE
SWITCHING REGULATORS
Electrical Characteristics: All Output Voltage Versions
(Specifications with standard type face are for TJ = 25°C, and those with bold face type apply over full Operating
Temperature rage. Unless otherwise specified, VIN = 12V for 3.3V, 5V, and Adjustable version, and VIN = 24V for
12V version, ILOAD = 500mA)
Parameter
Condition
Symbol
Min
Typ
Feedback Bias
Current
VFB =1.3V (Adjustable Version Only)
Ib
-
10
Oscillator
Frequency
(Note 6)
fo
Saturation
Voltage
IOUT = 3A (Notes 7, 8)
VSAT
Max Duty Cycle
(ON)
(Note 8)
DC
100
Min Duty Cycle
(OFF)
(Note 9)
DC
0
Current Limit
Peak Current (Notes 7, 8)
lCL
Output Leakage
Current
Output =0V (Notes 7, 9, 10)
Max
50
Unit
nA
100
127
173
150
110
kHz
173
1.4
-
1.16
Standby
Quiescent
Current
SD Pin = 5V (OFF), Note 10
%
%
A
-
-
100
µA
-
2
-
mA
lQ
-
5
-
mA
lSTBY
-
70
200
μA
Output = -0.9V (Note 10)
(Note 9)
-
3.4
lL
Quiescent
Current
V
1.5
SD Pin Logic
lnput Level
Low (ON)
VIH
-
1.3
0.6
High (OFF)
VIL
2.0
1.3
-
SD Pin lnput
Current
VLOGlC = 2.5V (OFF)
IH
5
15
μA
VLOGlC
IL
0.02
5
μA
V
= 0.5V (ON)
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating
Ratings indicate conditions for which the device is intended to be functional, but do not
guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical
Characteristics.
Note 2: The human body model is a 100pF capacitor discharged through a 1.5KΩresistor into each pin.
Note 3: Typical numbers are at 25°C and represent the most likely norm.
GM7230V2.02
Note 4: All limits guaranteed at room temperature (standard type face) and at temperature extremes (bold type
face). All room temperature limits are 100% production tested. All limits at temperature extremes are
guaranteed via correlation using standard Statistical Quality Control (SQC) methods. All limits are used to
calculate Average Outgoing Quality Level (AOQL).
6
Note 5: External components such as the catch diode, inductor, input and output capacitors, and voltage
programming resistors can affect switching regulator system performance. When the GM7230 is used as
shown in the Figure 1 test circuit, system performance will be as shown in system parameters section of
Electrical Characteristics.
Note 6: The switching frequency is reduced when the second stage current limit is activated.
Note 7: No diode, inductor or capacitor connected to output pin.
Note 8: Feedback pin removed from output and connected to 0V to force the output transistor switch ON.
Note 9: Feedback pin removed from output and connected to 12V for the 3.3V, 5V, and the ADJ. version.
GM7230
150KHz, 3A STEP DOWN VOLTAGE
SWITCHING REGULATORS
Test Circuit and Layout Guidelines
Careful layout is important with any switching regulators. Rapidly switching curren ts associated with
wiring inductance generate voltage transients which can cause problems. To minimize inductance
and ground loops, the lengths of the leads indicated by heavy lines in Figure 1&2 below should be
kept as short as possible. Single point grou nding (as indicated or ground plane construction should
be used for best results. When using the Adjustable version, place the programming resistors as
close as possible to GM7230, to keep the sensitive feedback wiring short.
4
Feedback
1
VIN
VIN
Unregulatedd
DC Input
L1
68μH
GM7230-x.x
3
GND
CIN
100μF
2
VOUT
VOUT
D1
5
ON/OFF
L
O
A
D
COUT
680μF
Figure 1 Fixed Ouput Votlage Versions
CIN = 470μF, Aluminum Electrolytic
COUT = 220μF, 25V, Aluminum Electrolytic
D1 = Schottky, 5A/40V
L1 = 68μH
VIN
VIN
Unregulatedd
DC Input
CIN
100μF
L1
68μH
GM7230-A
3
GND
VOUT
2
VOUT
5
ON/OFF
R2
D1
COUT
680μF
Figure 2 Adjustable Ouput Votlage Versions
CIN = 470μF, Aluminum Electrolytic
COUT = 220μF, 25V, Aluminum Electrolytic
D1 = Schottky, 5A/40V
L1 = 68μH
VOUT = VREF (1 + R2/R1)
R1
L
O
A
D
GM7230V2.02
1
4
Feedback
7
GM7230
150KHz, 3A STEP DOWN VOLTAGE
SWITCHING REGULATORS
Typical Performance Characteristics
Figure 3. Switch Saturation Voltage
Figure 4. Switch Current Limit
1.4
SWlTCH CURRENT LlMlT (A)
SATURATlON VOLTAGE (V)
5.5
VlN =12V
1.3
1.2
1.1
TJ = - 40°C
1.0
0.9
0.8
25°
C
125 °C
0.7
0.6
VlN = 12V
VOUT =5V
5.0
4.5
4.0
3.5
2
1
0
3
-50
4
25
50
75
100
125
ILOAD = 3A
1.0
ILOAD = 1A
0.8
24
16
Switch ON
12
0.6
-50 -25 0
25 50 75 100
JUNCTION TEMPERATURE (°C)
8
Switch OFF
4
0
-50
Figure 7. Shutdown Quiescent Current
4.5V < VIN < 40V
ISWITCH = 0
20
SWlTCH CURRENT (mA)
INPUT - OUTPUT DIFFERENTIAL
(V)
L = 33μH
RIND = 0.04
VOUT = VREG = 50mV
1.2
0
Figure 6. Operating Quiescent Current
Figure 5. Dropout Voltage
1.6
1.4
-25
JUNCTlON TEMPERATURE (°C)
SWlTCH CURRENT (A)
-25 0
25 50 75 100 125
JUNCTION TEMPERATURE (°C)
Figure 8. Minimum Operating Supply Voltage
150
5
VON/OFF = 5V
TJ = 25°C
SUPPLY VOLTAGE (V)
CURRENT (µA)
100
80
TJ = -40°C and 125°C
60
40
20
0
0
10
20
30
SUPPLY VOLTAGE (V)
1
VOUT = 1.23V
ILOAD = 120mA
160
VIN = 40V
TJ = -40°C and 125°C
155
FREQUENCY (kHz)
7
6
CURRENT(µA)
GM7230V2.02
2
Figure 10. Switching Frequency
8
8
3
0
-50 -25
0
25 50 75 100 125
JUNCTION TEMPERATURE (°C)
40
Figure 9. SD Pin Current (Sinking)
5
4
3
2
150
145
140
135
130
1
0
0
4
5
10
15
20
SD PlN VOLTAGE(V)
25
120
-50 -25
0
25 50 75 100 125
JUNCTION TEMPERATURE (°C)
GM7230
150KHz, 3A STEP DOWN VOLTAGE
SWITCHING REGULATORS
Package Outline Dimensions – TO-263-5
0.176 – 0.184
(4.47 – 4.67)
0.389– 0.408
(9.88 – 10.18)
0.046 – 0.054
(1.17 – 1.37)
0.061 – 0.069
(1.56 – 1.76)
0.322– 0.339
(8.20 – 8.60)
0.596– 0.612
(15.14 – 15.54)
0.028– 0.036
(0.71 – 0.91)
7°
3°
0.200– 0.216
(5.08 – 5.48)
0 -8°
0.067 Typ.
(1.70)
0.224– 0.272
(5.70 – 6.90)
0.092 – 0.108
(2.34 – 2.74)
0.012 – 0.021
(0.31 – 0.53)
Package Outline Dimensions – TO-220-5
0.048 – 0.052
(1.22 – 1.32)
0.400 + 0.015
0.400 – 0.005
(0.38+ 0.18)
(0.38 +- 0.03)
0.149 – 0.153
(3.78 – 3.89)
0.175 – 0.185
(4.45 – 4.75)
0.100 – 0.120
(2.54 – 3.05)
0.149 – 0.153
(3.78 – 3.89)
0.525 – 0.555
(13.34 – 14.10)
0.030 – 0.040
(0.76 – 1.02)
0.057 – 0.077
(1.45 – 1.96)
0.105 + 0.010
0.105 – 0.010
(2.67 + 0.25)
(2.67 +- 0.38)
0.015 + 0.007
0.015 – 0.001
(0.38+ 0.18)
(0.38 +- 0.03)
GM7230V2.02
0.330 – 0.350
(8.38 – 8.89)
9
GM7230
150KHz, 3A STEP DOWN VOLTAGE
SWITCHING REGULATORS
Package Outline Dimensions – TO-220B-5
0.046 – 0.054
(1.17 – 1.37)
0.176 – 0.184
(4.47 – 4.67)
0.394 – 0.408
(10.01 – 10.36)
0.149 – 0.153
(3.79 – 3.89)
0.138 – 0.142
(3.51 – 3.61)
0.327 – 0.366
(8.30 – 9.30)
0.988 – 1.130
(25.1 – 28.7)
0.957 – 1.028
(24.3 – 26.1)
0.049 – 0.142
(1.25 – 3.60)
0.099 – 0.111
(2.52 – 2.82)
0.218 – 0.383
(5.53 – 9.75)
0.150 – 0.254
(3.80 – 6.45)
0.220 typ
(1.70 typ)
0.264 – 0.272
(6.70 – 6.90)
0.156 – 0.179
(3.95 – 4.55)
0.299 – 0.337
(7.60 – 8.55)
GM7230V2.02
Inches
(mm)
10
GM7230
150KHz, 3A STEP DOWN VOLTAGE
SWITCHING REGULATORS
Ordering Number
GM 7230 A
TA5
R
APM
Gamma
Micro
Package Type
Shipping Type
TA5: TO263-5
TB5: TO-220-5
TB5B: TO-220B-5
R: Taping & Reel
T: Tube
Circuit
Type
Output
Voltage
A: Adj
3.3 = 3.3V
5.0 = 5.0V
12 = 12.0V
G
Blank: Pb-Free
G: Green
Note:
Pb-free products:

RoHS compliant and compatible with the current require-ments of IPC/JEDEC J-STD-020.

Suitable for use in Pb-free soldering processes with 100% matte tin (Sn) plating.

Lead-free (RoHS compliant)

Halogen free(Br or Cl does not exceed 900ppm by weight in homogeneous material and total of
Br and Cl does not exceed 1500ppm by weight)
GM7230V2.02
Green products:
11