ACT2103-001
ACT2103
Rev 2, 23-May-12
18V/3A Step-Down DC/DC Converter
FEATURES GENERAL DESCRIPTION
3A Output Current
ACT2103 is a monolithic synchronous buck
regulator. The device integrates two 85m
Wide 4.5V to 18V Operating Input Range
MOSFETs, and provides 3A of continuous load
Synchronous Buck Topology
current over a wide input voltage of 4.5V to 18V.
Integrated 85m Power MOSFET Switches
Current mode control provides fast transient
Output Adjustable from 0.923V to 12V response and cycle-by-cycle current limit. Hiccup at
short circuit reduces IC temperatures.
Up to 96% Efficiency
An internal soft-start prevents inrush current at turn-
Stable with Low ESR Ceramic Output
on, and in shutdown mode the supply current drops
Capacitors
to 10 A. Pulse-skipping mode at light load reduces
Internal Soft Start
standby power down to 3mA.
3mA Low Standby Input Current
This device, available in an 8-pin SOP-8EP
High Light Load Efficiency
package, provides a very compact solution with
Cycle-by-Cycle Over Current Limit
minimal external components.
Input Under Voltage Lockout
Hiccup Protection at Short Circuit and Over
Current
Frequency Fold Back Protection
Low Power Dissipation at Over Current and
Short Circuit
APPLICATIONS
LCD-TV
Set-top Box
Distributed Power Systems
Networking Systems
Efficiency vs. Load Current
100
95
V = 7V
IN
90
85
V = 18V
IN
80
75
70 V = 12V
IN
65
60 V = 5V
OUT
55
10 100 1000 10000
Load Current (mA)
TM
Innovative Power - 1 - www.active-semi.com
Copyright 2012 Active-Semi, Inc.
Efficiency (%)
ACT2103
Rev 2, 23-May-12
ORDERING INFORMATION
PART NUMBER OPERATION TEMPERATURE RANGE PACKAGE PINS PACKING
ACT2103YH-T -40C to 85C SOP-8EP 8 TAPE & REEL
PIN CONFIGURATION
PIN DESCRIPTIONS
PIN NAME DESCRIPTION
High-Side Bias Input. This pin acts as the positive rail for the high-side switch's gate
1 HSB
driver. Connect a 10nF or greater capacitor between HSB and SW pins.
Input Supply. Bypass this pin to GND with a low ESR capacitor. Drive IN with a 4.5V to
2 IN
18V power source. See Input Capacitor in the Application Information section.
Switch Output. Connect this pin to the switching end of the external inductor. Note that
3 SW
a capacitor is required from SW to HSB to power the high-side switch.
4 GND Ground.
Feedback Input. FB senses the output voltage to regulate that voltage. Drive FB with a
5 FB resistive voltage divider from the output voltage. The feedback threshold is 0.923V.
See Setting the Output Voltage.
Compensation Node. COMP is used to compensate the regulation control loop. See
6 COMP
Compensation Components.
Enable Input. When higher than 2.5V, this pin turns the IC on. When lower than 2.3V,
7 EN this pin turns IC off. When left unconnected, EN is pulled up to logic HIGH with a 2A
pull-up current. EN is a digital input that turns the regulator on or off.
8 N/C Not connected.
TM
Innovative Power - 2 - www.active-semi.com
Copyright 2012 Active-Semi, Inc.