Description
GM6605 series of positive adjustable and fixed regulators
is designed to provide 5A output with low dropout voltage
performance. On-chip trimming adjusts the reference volt-
age with an accuracy of ±1% for adjustable, and ±2% for
fixed voltage versions. To work in post regulators or micro-
processor power supplies, which where low voltage opera-
tion and fast transient response are required. Device in-
cludes over-current protection and thermal shutdown pro-
tection as well.
GM6605 is available in TO-220 and surface-mount TO-263
packages.
Features
Adjustable or Fixed Output
Output Current of 5.0A
Dropout Voltage (typical) 1.15V @ 5.0A
Typical Line Regulation 0.04%
Typical Load Regulation 0.08%
Fast Transient Response
Current Limit Protection
Thermal Shutdown Protection
Application
Microprocessor Supply
Post Regulators for Switching Supplies
Telecommunication Systems
Medical Equipment
Printer Supplies
Motherboards
TYPICAL APPLICATION CIRCUITS
V
IN
5.0V
ADJ
V
OUT
3.3V@3.0A
124W
1.0%
5.0V
V
IN
V
OUT
GM6605-Adj
GM6605-3.3
GND
3.3V@3.0A
(Adjustable Version)
(Fixed Version)
www.gammamicro.com
GM6605
V0.11
1
10µF
5.0V
0.1µF
5.0V
200W
1.0%
22µF
5.0V
10µF
5.0V
22µF
5.0V
MARKING INFORMATION & PIN CONFIGURATIONS
(Top View)
TO-252 (DPAK)
TO-220
TO-263-2 (D PAK)
2
GM6605
VVAYWW
GM6605
VVAYWW
GM6605
VVAYWW
V
IN
V
OUT
GND*
V
IN
V
OUT
GND*
V V = Output Voltage (50 = 5.0V, A =Ad
j
)
A
= Assembly Location
Y
= Year
W W = Weekly
V
IN
V
OUT
GND*
On fixed versions Pin 1 = GND,
on adjustable versions Pin 1 = ADJ
Tab = V
OUT
ORDERING INFORMATION
Ordering Number
GM6605-ATA3T
GM6605-ATA3R
GM6605-ATB3T
GM6605-1.8TA3T
GM6605-1.8TA3R
GM6605-1.8TB3T
GM6605-2.5TA3T
GM6605-2.5TA3R
GM6605-2.5TB3T
GM6605-3.3TA3T
GM6605-3.3TA3R
GM6605-3.3TB3T
GM6605-3.3TC3T
GM6605-3.3TC3R
Output Voltage
Adj
Adj
Adj
1.8
1.8
1.8
2.5
2.5
2.5
3.3
3.3
3.3
3.3
3.3
5.0
5.0
5.0
Package
TO-263-2
TO-263-2
TO-220
TO-263-2
TO-263-2
TO-220
TO-263-2
TO-263-2
TO-220
TO-263-2
TO-263-2
TO-220
TO-252
TO-252
TO-263-2
TO-263-2
TO-220
Shipping
50 Units / Tube
800 Units / Tape & Reel
50 Units / Tube
50 Units / Tube
800 Units / Tape & Reel
50 Units / Tube
50 Units / Tube
800 Units / Tape & Reel
50 Units / Tube
50 Units / Tube
800 Units / Tape & Reel
50 Units / Tube
80 Units / Tube
2,500 Units / Tape & Reel
50 Units / Tube
800 Units / Tape & Reel
50 Units / Tube
GM6605
GM6605-5.0TA3T
GM6605-5.0TA3R
GM6605-5.0TB3T
* For detail Ordering Number identification, please see last page.
2
ABSOLUTE MAXIMUM RATINGS
PARAMETER
Power Dissipation
Input Voltage
Junction Temperature
Lead Temperature(Soldering, 10sec)
SYMBOL
P
D
V
IN
T
J
T
LEAD
T
J
T
STG
VALUE
Internally limited
15
+150
300
0 to + 125
-65 to + 150
UNIT
W
V
°C
°C
°C
°C
Operating Junction Temperature Range
Storage Temperature Range
BLOCK DIAGRAM
(Fixed Version)
V
OUT
V
IN
Thermal
Shutdown
-
Bandgap
Reference
+
Error
Amplifier
Output
Current
Limit
GND
(Adjustable Version)
V
OUT
V
IN
-
Bandgap
Reference
+
ADJ
GM6605
3
Thermal
Shutdown
Error
Amplifier
Output
Current
Limit
ELECTRICAL CHARACTERISTICS
(Typicals and limits appearing in normal type apply for T
J
= 25°C)
Parameter
Reference Voltage
GM6605-Adj
GM6605-1.8
GM6605-2.5
Output Voltage
GM6605-3.3
GM6605-5.0
GM6605-Adj
GM6605-1.8
Line Regulation
GM6605-2.5
GM6605-3.3
GM6605-5.0
GM6605-Adj
GM6605-1.8
Load Regulation
GM6605-2.5
GM6605-3.3
GM6605-5.0
Dropout Voltage
Current Limit
Minimum Load Current
GM6605-Adj
GM6605-1.8
GM6605-2.5
Quiescent Current
GM6605-3.3
GM6605-5.0
Adjust Pin Current
Temperature Coefficient
Ripple Rejection
R
A
GM6605-Adj
I
ADJ
I
Q
V
D
I
CL
I
O MIN
REG
LOAD
REG
LINE
V
O
Symbol
V
REF
Condition
I
OUT
=10mA, V
IN
-V
OUT
=1.5V
10mA I
OUT
5A, 3.3V V
IN
7V
I
OUT
=10mA, V
IN
=3.3V
10mA I
OUT
5A, 3.3V V
IN
7V
I
OUT
=10mA, V
IN
=4V
10mA I
OUT
5A, 4V V
IN
7V
I
OUT
=10mA, V
IN
=4.8V
10mA I
OUT
5A, 4.8V V
IN
7V
I
OUT
=10mA, V
IN
=6.5V
10mA
I
OUT
5A, 6.5V V
IN
7V
I
OUT
=10mA,
I
OUT
=10mA, 3.3V
I
OUT
=10mA, 4V
I
OUT
=10mA, 4.8V
I
OUT
=10mA, 6.5V
V
IN
V
IN
V
IN
V
IN
7V
7V
7V
7V
5A
Min
1.238
1.230
1.782
1.764
2.475
2.460
3.267
3.247
4.950
4.920
Typ
1.250
1.250
1.800
1.800
2.500
2.500
3.300
3.300
5.000
5.000
0.04
0.04
0.04
0.04
0.04
0.08
0.08
0.08
0.08
0.08
1.15
Max
1.262
1.270
1.818
1.836
2.525
2.540
3.333
3.353
5.050
5.080
0.20
0.20
0.20
0.20
0.20
0.40
0.40
0.40
0.40
0.40
1.3
Unit
V
V
V
V
V
%
V
IN
-V
OUT
=1.5V, 10mA I
O
V
IN
=3.8V, 10mA I
O
V
IN
=4.5V, 10mA I
O
V
IN
=5.3V, 10mA I
O
V
IN
=7V, 10mA I
O
5A
5A
5A
5A
%
I
OUT
=5A
V
IN
-V
OUT
=3V
V
IN
=5V
V
IN
=3.3V, 10mA I
O
V
IN
=4.0V, 10mA I
O
V
IN
=4.8V, 10mA I
O
V
IN
=6.5V, 10mA I
O
5A
5A
5A
5A
V
A
5.5
6.8
5
5
5
5
5
10
10
10
mA
mA
10
10
120
µA
%/°C
dB
I
OUT
=10mA, 2.75V
V
IN
7V
50
0.005
60
80
V
IN
-V
OUT
=1.5V, I
OUT
=10mA
V
IN
-V
OUT
=1.5V, I
OUT
=5A
GM6605
4
APPLICATION INFORMATION
GM6605 series linear regulators provide fixed and ad-
justable output voltages at currents up to 5.0A. These
regulators are protected against over-current condi-
tions and include thermal shutdown protection. The
GM6605 has a composite PNP-NPN output transistor
and require an output capacitor for stability.
A detailed procedure for selecting this capacitor is as
followed.
Protection Diodes
When large external capacitors are used with most
linear regulator, it is wise to add protection diodes. If
the input voltage of the regulator is shorted, the out-
put capacitor will discharge into the output of the reg-
ulator. The discharge current depends on the value
of capacitor, output voltage, and rate at which V
IN
drops.
Figure 1
(a),(b)
Stability Considerations
The output compensation capacitor helps to determine
three main characteristics of a linear regulator's perfor-
mance: start-up delay, load transient response, and
loop stability. The capacitor value and type is based on
cost, availability, size, and temperature constraints. A
tantalum or aluminum electrolytic capacitor is pre-
ferred, as a film or ceramic capacitor with almost zero
ESR can cause instability. An aluminum electrolytic ca-
pacitor is the least expensive type. But when the circuit
operates at low temperatures, both the value and ESR
of the capacitor will vary widely. For optimum perfor-
mance over the full operating temperature range, a tan-
talum capacitor is the best. A 22µF tantalum capacitor
will work fine in most applications. But with high current
regulators, such as GM6605 higher capacitance values
will improve the transient response and stability. Most
applications for Gm6605 involve large changes in load
current, so the output capacitor must supply instanta-
neous load current. The ESR of the output capacitor
causes an immediate drop in output voltage given by:
C1
V
IN
C1
Protection Diode Scheme for
Large Output Capacitors
(a) Fixed Version
IN4002
V
IN
V
IN
V
OUT
V
OUT
GM6605-3.3
GND
C2
(b) Adjustable Version
V
IN
IN4002
V
OUT
V
OUT
GM6605-Adj
ADJ
R1
C
ADJ
C2
R2
DV
=
D
I x ESD
In microprocessor applications an output capacitor net-
work of several tantalum and ceramic capacitors in par-
allel is commonly used. This reduces overall ESR and
minimizes the instantaneous output voltage drop under
transient load conditions. The output capacitor network
should be placed as close to the load as possible for
the best results.
In GM6605 linear regulators, the discharge path is
through a large junction, and protection diodes are
normally not needed. However, if the regulator is
used with large output capacitance values and the in-
put voltage is instantaneously shorted to ground,
as shown above in Figure 1.
damage can occur. In this case, a diode connected
GM6605
5
