input voltage range of 4.5 to 30V while maintaining
1mA of supply current at no load.
The output
voltage is either factor programmed or set via two
external resistors to as low as 1.23V.
The regulator operates at fixed 150kHz switching
frequency ensuring low output ripple across the
entire load.
It requires only four external
components for minimum PCB footprint and lowest
overall system cost. An independent Enable pin
provides electrical On/Off of the regulator. When
connected to logic high, the regulator shuts down
and consumes less than 100µA of current. Excellent
transient response is achieved with no external
compensation components.
The device provides under-voltage lockout, output
short circuit and over-temperature protection to
safeguard the device and under fault conditions. An
integrated soft-start controls the ramp of the output
voltage and minimizes the inrush current.
The AMS2596 is available in SOIC, TO220, TO252
and TO263 packages, and it is rated for -25 to
+125°C temperature range.
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
V
IN
range: 4.5 - 30V
V
OUT
range: 1.25V to 7V fixed output Voltage
in 100mV steps
Adjustable version output voltage range
from 1.2V to 25V
Up to 5A output current
150kHz switching frequency
900µA supply current
80uA standby quiescent current
100% Duty Cycle
Excellent line and load regulation
Internal Soft Start
Internal compensation
Under voltage lockout
Current Limit Protection
Over temperature protection
-25°C to +125°C Temperature Range
Available in SOIC-8, TO220-5, TO252-5 and
TO263-5 packages
Applications
•
•
•
•
LCD Monitor and TV
High Current Point of Load Regulator
System Power
Set Top Box
Typical Application
12V
4
2
3
7
U1
Vin
EN
n/c
LX
LX
FB
6
5
1
8
R2
10.0k
L1
33uH
D1
B540C
R1
31.7k
2.5V
C1
470uF
C2
470uF
gnd
gnd
AMS2596
3/4/2010
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1
Phone (925) 443-0722
Fax (925) 443-0723
AMS2596
3A 30V Step-Down Converter
Pin Description
TO-263
TO-220
TO-252
Pin#
1
2
3, tab
4
5
N/A
SOIC-8
Pin#
4
5, 6
7, 8
1
2
3
9
Symbol
V
IN
LX
GND
FB
EN
NC
GND
(PADDLE)
Description
Input supply pin. Connect a capacitor between this pin and ground.
Switching node - connect an inductor between this pin and the output
capacitor.
Ground connection.
Feedback pin. Connect this pin to the center tab of the resistor divider.
Enable pin. Logic high shuts the device down and consumes 50µA of
current. When connected to logic low, the device will resume normal
operation. This pin should not be floating.
No connect.
Ground paddle to be connected to PCB ground plane.
Pin Configuration
8L SOIC
SO Package (S)
Top View
3/4/2010
www.advanced-monolithic.com
2
Phone (925) 443-0722
Fax (925) 443-0723
AMS2596
3A 30V Step-Down Converter
Absolute Maximum Ratings
(1)
V
IN
Supply Voltage………………...….......…..….-0.3V to 30V
FB feedback pin……………………...........……-0.3V to +30V
EN Enable Voltage…………………….…....….-0.3V to +20V
Storage Temperature Range…………...…...-65⁰C to 150⁰C
Lead Temperature (Soldering 60se………….….…… 215⁰C
Junction Temperature………...……………….….…… 150⁰C
ESD Suceptability…………………………………………..2kV
Recommended Operating Conditions
(2)
Input Voltage……………………………………..………..4.5V to 28 V
Tj Operating Temperature…… ……………….…….-25⁰C to 125⁰C
Thermal Information
8L SOIC EP
θ
JA
………………………………….….…...60⁰C/W
(9)
……………………………….….….…....30⁰C/W
TO263-5
θ
JA
(10)
………………………………….….…....57⁰C/W
TO-252
θ
JA
(8)
…………………………….….…….…….50⁰C/W
TO-220
θ
JA
(11)
Electrical Characteristics
Parameter
V
in
Feedback Voltage
Efficiency
Oscillator Frequency
Saturation Voltage
Maximum Duty Cycle
Minimum Duty Cycle
Current Limit
Shutdown Supply Current
Output Leakage Current
Quiescent Current
Standby Quiescent Current
Enable Logic Input
Threshold Voltage
T
A
= 25
°C
and V
IN
=12V (unless otherwise noted).
Symbol
V
in
V
FBSW
η
F
OSC
V
SAT
D
MAX
D
MIN
I
LIMSW
I
Vinsd
I
LK
I
Q
I
SD
I
SW out
=3A
Note 6
Note 7
V
SW out
=5V
V
EN
=0V
Output = 0V (Note 8)
Output = -1V
(Note 6)
ON/OFF pin = 5V (OFF)
3.6 / 3.4
4.5V
≤
VIN
≤
30V,
0.2A
≤
ILoad
≤
3A
VIN = 12V, V
OUT
= 3V, ILoad = 3A
Conditions
Min.
4.5
1.193
1.180
85
127
150
1.16
95
0
4.5
90
2
5
80
1.3
V
EN(L)
V
EN(H)
I
ENH
I
ENL
Low (Regulator ON)
High (Regulator OFF)
V
LOGIC
= 2.5V (Regular OFF)
V
LOGIC
= 0.5V (Regular ON)
5
0.02
5
0.02
125
0.6
2.0
15
5
50
30
10
200
250
6.9 / 7.5
Typ.
12
1.230
Max.
20
1.267
1.280
%
173
1.4/1.5
99
kHz
V
%
%
A
nA
μA
mA
μA
V
V
V
µA
µA
°C
Units
V
V
Enable Input Current
Over-temperature
Sh td
Notes:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
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.
V
O
= Output Voltage specified from 1.25V to 7V in 100mV increments.
Typical numbers are at 25ºC and represent the most likely norm.
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).
Feedback pin removed from output and connected to 0V to force the output transistor switch ON.
Feedback pin removed from output and connected to 12V for Fixed and Adjustable version, to force the output transistor switch OFF.
With output transistor switch turned off.
Junction to ambient thermal resistance (no external heat sink) for the TO-220 package mounted vertically, with the leads soldered to a printed circuit
board with (1 oz.) and a heat sink approximately 1 in
2
.
Junction to ambient thermal resistance with the TO-263 package tab soldered to a double side printed circuit board with 2.5 in
2
of (1 oz.) copper area.
Junction to ambient thermal resistance with the TO-252 package tab soldered to a single sided printed circuit board with 2.5 in
2
of (1 oz.) copper area.
Junction to ambient thermal resistance with the SO-8 EDP package soldered to a double sided printed circuit board 5 via under the package paddle
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