A8697
Wide Input Voltage 4.0 A Step Down Regulator
Features and Benefits
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8 to 25 V input range
Integrated DMOS switch
Adjustable fixed off-time
Adjustable output
Description
The A8697 is a constant off-time current mode step-down
regulator with a wide input voltage range. Regulation voltage is
set by external resistors, to output voltages as low as 0.8 V.
The A8697 includes an integrated power DMOS switch to
reduce the total solution footprint. It also features internal
compensation, allowing users to design stable regulators with
minimal design efforts.
The off-time can be set with an external resistor, allowing
flexibility in inductor selection. Additionally, the A8697 has
a logic level enable pin which can shut the device down and
put it into a low quiescent current mode for power sensitive
applications.
Package: 8-Lead SOIC with exposed
thermal pad (suffix LJ)
The A8697 is supplied in a low-profile 8-lead SOIC with
exposed pad (package LJ). Applications include:
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Applications with 8 to 25 V input
Consumer electronics, networking equipment
12 V lighter-powered applications (portable DVD, etc.)
Point of Sale (POS) applications
Approximate Scale 1:1
Typical Application
V
IN
+12 V
CBOOT
0.01
μF
Efficiency versus Load Current
90
80
70
VOUT = 2.5 V
+
CIN
47
μF
25 V
BOOT
VIN
V
OUT
1.06 V/ 4.0 A
VOUT = 1.8 V
VOUT = 1.06 V
Efficiency (%)
60
50
40
30
20
10
0
0
1
2
3
4
ENB
A8697
TSET
RTSET
51.1 k
GND
Ratings:
L: CDRH104R-3R8
COUT: EEUFM1V151
CIN: EEVFC1H470P
LX
L
3.8
μH
D1
R1
2k
VBIAS
+
COUT
150
μF
56 mΩ
FB
R2
6.14 k
Load Current (A)
Circuit for 12 V step down to 1.06 V at 4 A
A8697-DS, Rev. 2
Efficiency curve for circuit at left
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