GAMMA GM2576-AS8R

GM2576
2A STEP DOWN VOLTAGE SWITCHING
REGULATORS
Description
Features
GM2576 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 2A line and load regulations. GM2576 is
available in fixed output voltages of 3.3V, 5V,
and a versatile Adjustable output version.
‹
Standard SOP8 & PSOP8 and 5L TO252
packages are available
‹
3.3V, 5V, and Adjustable output versions
‹
Adjustable version output voltage range
1.23V to 37V
These regulators are simple to use and require
minimum number of external components. The
features include internal frequency compensation
and a fixed-frequency oscillator.
‹
VOUT accuracy is to ±1.8% under specified
input voltage and output load conditions
‹
Input voltage range up to 40V
The GM2576 is high-efficiency replacements for
popular three-terminal linear regulators, and is
requiring a smaller heat sink or even no need
heat sink.
‹
Requires only 4 external components with
High efficiency
‹
TTL shutdown capability, low power
standby mode
GM2576 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.
‹
Built-in thermal shutdown, current limit
protection
‹
Uses standard inductors
‹
52 kHz fixed frequency internal oscillator
GM2576 operates at a switching frequency of
52 kHz which allowing smaller size filter
components than what would be needed with
lower frequency switching regulators.
GM2576 series are available in a standard 8-lead
SO package, 8 lead SO package with heat sink
or 5L TO252 package.
Application
Pre-regulator for linear regulators
On-card/board switching regulators
High-efficiency step-down buck regulator
Positive to negative converter (buck-boost)
Typical Application Circuits
GM2576-5.0
FB
VIN
Output
CIN
100µF
SD
L1
100µH
5V
regulated
output,
GND
D1
1N5822
COUT
680µF
www.gammamicro.com.tw
GM2576V1.30
7V – 40V
Unregulated
DC Input
1
GM2576
2A STEP DOWN VOLTAGE SWITCHING
REGULATORS
Marking Information and Pin Configurations (Top View)
SO8 & PSO8
GND
GND
5L TO-252
GND
GND
GM2576G
VVAYWW
GM2576
VVVAYWW
SD
FB
VVV: 033=3.3V, 050=5.0V, 00A=ADJ
A: Assembly / Testing factory code
Y: Year
WW: Week
5.SD
4.FB
3.GND
2. VOUT
1. VIN
VIN
VOUT
VV: 33=3.3V, 50=5.0V, A=ADJ
A: Assembly / Testing factory code
Y: Year
WW: Week
Ordering Information
GM2576V1.30
Ordering Number
2
Output Voltage
Package
Shipping
GM2576-AS8T
Adj
SOP8
100 Units / Tube
GM2576-AS8R
Adj
SOP8
2500 Units / Reel
GM2576-APS8T
Adj
PSOP8
100 Units / Tube
GM2576-APS8R
Adj
PSOP8
2500 Units / Reel
GM2576-ATC5RG
Adj
5L-TO252
50 Units / Tube
GM2576-3.3S8T
3.3
SOP8
100 Units / Tube
GM2576-3.3S8R
3.3
SOP8
2500 Units / Reel
GM2576-3.3PS8T
3.3
PSOP8
100 Units / Tube
GM2576-3.3PS8R
3.3
PSOP8
2500 Units / Reel
GM2576-3.3TC5RG
3.3
5L-TO252
50 Units / Tube
GM2576-5.0S8T
5.0
SOP8
100 Units / Tube
GM2576-5.0S8R
5.0
SOP8
2500 Units / Reel
GM2576-5.0PS8T
5.0
PSOP8
100 Units / Tube
GM2576-5.0PS8R
5.0
PSOP8
2500 Units / Reel
GM2576-3.3TC5RG
5.0
5L-TO252
50 Units / Tube
GM2576
2A 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 (θJA)
** 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
VIN
FB
R2*
Regulator
With
Enable
Error
Amplifier
Comparator
SD
Driver
R1*
1.23V
Reference
Gnd
52KHz
Oscillator
Reset
Thermal Shutdown
&
Current Limit
VOUT
GM2576V1.30
VOUT = 3.3V, R1 = 2.49K, R2 = 4.18K
VOUT = 5.0V, R1 = 2.49K, R2 = 7.57K
VOUT = ADJ, R1 = OPEN, R2 = 0Ω
3
GM2576
2A STEP DOWN VOLTAGE SWITCHING
REGULATORS
Electrical Characteristics: GM2576-ADJ
(Specifications with standard type face are for T = 25℃, and those with bold face type apply over full Operating Temperature
rage)
Parameter
Feedback
Voltage
Efficiency
Condition
Symbol
VIN =12V, ILOAD = 0.2A, VOUT is set to 5V
4.5V < VIN < 40V, 0.2A < ILOAD < 2A,
VOUT is set to 5V
VIN =12V, ILOAD=2.0A, VOUT = 5V
VFB
Min
Typ
Max
1.217
1.230
1.243
1.208
1.180
η
1.230
Unit
V
1.252
1.280
77
%
Electrical Characteristics: GM2576-3.3
(Specifications with standard type face are for T = 25℃, and those with bold face type apply over full Operating Temperature
rage)
Parameter
Condition
Output Voltage
4.5V < VIN < 40V, 0.2A < ILOAD < 2A
Efficiency
VIN =12V, ILOAD=2.0A,
Symbol
VOUT
Min
3.163
3.201
η
Typ
3.300
Max
Unit
3.390
V
3.432
73
%
Electrical Characteristics: GM2576-5.0
GM2576V1.30
(Specifications with standard type face are for T = 25℃, and those with bold face type apply over full Operating Temperature
rage)
4
Parameter
Condition
Output Voltage
4.5V < VIN < 40V, 0.2A < ILOAD < 2A
Efficiency
VIN =12V, ILOAD=2.0A
Symbol
VOUT
η
Min
4.850
4.800
Typ
5.000
77
Max
5.150
5.200
Unit
V
%
GM2576
2A STEP DOWN VOLTAGE SWITCHING
REGULATORS
Electrical Characteristics: All Output Voltage Versions
(Specifications with standard type face are for T = 25℃, and those with bold face type apply over full Operating Temperature
rage)
Parameter
Condition
Symbol
Min
Typ
Feedback Bias
Current
VFB =5V (Adjustable Version Only)
Ib
-
50
Oscillator
Frequency
(Note 3)
fo
42
52
Saturation
Voltage
lOUT = 2A (Notes 4, 5)
VSAT
-
1.4
Max Duty Cycle
(ON)
(Note 5)
DC
Current Limit
Peak Current (Notes 4, 5)
lCL
100
Unit
nA
500
58
1.8
kHz
V
2.0
93
3.6
98
4.5
3.4
Output Leakage
Current
Max
Output =0V (Notes 4, 6)
Output = -1V (Notes 4, 6)
Quiescent
Current
(Note 6)
Standby
Quiescent
Current
SD Pin = 5V (OFF)
Low (ON)
lL
-
6.9
A
7.5
7.5
2
mA
30
lQ
-
5
10
mA
lSTBY
-
50
200
µA
VIH
-
1.2
1.0
0.8
SD Pin Logic
lnput Level
High (OFF)
%
VIL
2.2
1.4
-
V
2.4
VLOGlC = 2.5V (OFF)
IH
12
30
VLOGlC = 0.5V (ON)
IL
0
10
µA
Note 1:
Stresses greater than those listed under Maximum Ratings may cause permanent damage to
the device. This is a stress rating only and functional operation of the device at these or any
other conditions above those indicated in the operation is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect reliability.
Note 2:
The human body model is a 100pF capacitor discharge through a 1.5KΩ resistor into each pin.
Note 3:
External components such as the catch diode, inductor, input and output capacitors, and voltage
programming resistors can affect switching regulator system performance. Where the GM2576
is used as shown in Figure 1&2 test circuits.
Note 4:
No diode, inductor or capacitor connected to output pin.
Note 5:
Feedback pin removed from output and connected to 0V to force the output transistor switch ON.
Note 6:
Feedback pin removed from output and connected to 12V for the 3.V, 5V and Adj version, to
force the output transistor switch OFF.
GM2576V1.30
SD Pin lnput
Current
5
GM2576
2A STEP DOWN VOLTAGE SWITCHING
REGULATORS
Test Circuit and Layout Guidelines
Careful layout is important with any switching regulators. Rapidly switching currents 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 grounding (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 GM2576, to keep the sensitive feedback wiring short.
FB
VIN
GM2576-x.x
L1
100µH
VOUT
VOUT
D1
VIN
Unregulatedd
DC Input
CIN
100µF
L
O
A
D
COUT
680µF
SD
GND
Figure 1 Fixed Ouput Votlage Versions
CIN = 100µF, Aluminum Electrolytic
COUT = 680µF, 25V, Aluminum Electrolytic
D1 = Schottky
L1 = 100µH
FB
VIN
L1
100µH
GM2576-A
VOUT
VOUT
GM2576V1.30
VIN
Unregulatedd
DC Input
6
R2
CIN
100µF
GND
SD
D1
COUT
680µF
Figure 2 Adjustable Ouput Votlage Versions
CIN = 100µF, Aluminum Electrolytic
COUT = 680µF, 25V, Aluminum Electrolytic
D1 = Schottky
L1 = 100µH
VOUT = VREF (1 + R2/R1)
where VREF = 1.23V and R1 is between 1K to 5K
R1
L
O
A
D
GM2576
2A STEP DOWN VOLTAGE SWITCHING
REGULATORS
Package Outline Dimensions – SO 8
0.189 - 0.197
(4.800 - 5.004)
0.228 - 0.244
(5.791 - 6.198)
0.016 - 0.050
(0.406 - 0.270)
D
0.014 - 0.020
(0.356 - 0.508)
0.050
(1.270)
TYP
0.150 - 0.157
(3.810 - 3.988)
0.053 - 0.059
(1.346 - 1.753)
SEATING PLAN
0.004 - 0.010
(0.012 - 0.254)
0.008 - 0.010
(0.203 - 0.254)
8.0
MAX
Package Outline Dimensions – PSO 8
0.189 - 0.197
(4.800 - 5.004)
0.090
(2.286)
0.095 - 0.130 0.228 - 0.244
(2.410 - 3.300) (5.791 - 6.198)
0.016 - 0.050
(0.406 - 0.270)
0.050
(1.270)
TYP
0.150 - 0.157
(3.810 - 3.988)
0.053 - 0.059
(1.346 - 1.753)
SEATING PLAN
0.004 - 0.010
(0.012 - 0.254)
0.008 - 0.010
(0.203 - 0.254)
8.0
MAX
GM2576V1.30
D
0.014 - 0.020
(0.356 - 0.508)
7
GM2576
2A STEP DOWN VOLTAGE SWITCHING
REGULATORS
Package Outline Dimensions – 5L TO252
0.250 – 0.262
(6.350 – 6.650)
0.087 – 0.094
(2.200 – 2.400)
0.205 – 0.213
(5.200 – 5.400)
0.374 – 0.390
(9.500 – 9.900)
0.017 – 0.023
(0.430 – 0.580)
0.150 REF
(3.800)
0.213 – 0.224
(5.400 – 5.700)
0.000 – 0.005
(0.000 – 0.127)
0.100 – 0.114
(2.550 – 2.900)
0.050 TYP.
(1.27)
0.016 – 0.024
(0.400 – 0.600)
GM2576V1.30
1.00 TYP.
(2.540)
8
0.055 – 0.070
(1.400 – 1.780)
0.017 – 0.023
(0.430 – 0.580)
GM2576
2A STEP DOWN VOLTAGE SWITCHING
REGULATORS
Ordering Number
GM 2576 A
APM Gamma
R
Output Voltage
Package Type
Shipping Type
A: Adj
3.3 = 3.3V
5.0 =5.0V
S8: SO 8
PS8: Power SO 8
TA5: 5L TO252
R: Taping & Reel
T: Tube
GM2576V1.30
Micro
Circuit Type
S8
8
10
6
9