Rainbow Electronics MAX15026 - Manual

General Description
The MAX15026 synchronous step-down controller oper-
ates from a 4.5V to 28V input voltage range and gener-
ates an adjustable output voltage from 85% of the input
voltage down to 0.6V while supporting loads up to 25A.
The device allows monotonic startup into a prebiased
bus without discharging the output and features adap-
tive internal digital soft-start.
The MAX15026 offers the ability to adjust the switching
frequency from 200kHz to 2MHz with an external resis-
tor. The MAX15026’s adaptive synchronous rectification
eliminates the need for an external freewheeling
Schottky diode. The device also utilizes the external
low-side MOSFET’s on-resistance as a current-sense
element, eliminating the need for a current-sense resis-
tor. This protects the DC-DC components from damage
during output overloaded conditions or output short-
circuit faults without requiring a current-sense resistor.
Hiccup-mode current limit reduces power dissipation
during short-circuit conditions. The MAX15026 includes
a power-good output and an enable input with precise
turn-on/turn-off threshold, which can be used for input
supply monitoring and for power sequencing.
Additional protection features include sink-mode cur-
rent limit and thermal shutdown.
Sink-mode current limit prevents reverse inductor cur-
rent from reaching dangerous levels when the device is
sinking current from the output.
The MAX15026 is available in a space-saving and ther-
mally enhanced 3mm x 3mm, 14-pin TDFN-EP pack-
age. The MAX15026 operates over the -40°C to +85°C
temperature range.
Applications
Set-Top Boxes
LCD TV Secondary Supplies
Switches/Routers
Power Modules
DSP Power Supplies
Points-of-Load Regulators
Features
♦ 4.5V to 28V or 5V ±10% Input Supply Range
♦ 0.6V to (0.85 x V
IN ) Adjustable Output
♦ Adjustable 200kHz to 2MHz Switching Frequency
♦ Ability to Start into a Prebiased Load
♦ Lossless, Cycle-by-Cycle Valley Mode Current
Limit with Adjustable, Temperature-Compensated
Threshold
♦ Sink-Mode Current-Limit Protection
♦ Adaptive Internal Digital Soft-Start
♦ ±1% Accurate Voltage Reference
♦ Internal Boost Diode
♦ Adaptive Synchronous Rectification Eliminates
External Freewheeling Schottky Diode
♦ Hiccup-Mode Short-Circuit Protection
♦ Thermal Shutdown
♦ Power-Good Output and Enable Input for Power
Sequencing
♦ ±5% Accurate Enable Input Threshold
MAX15026
Low-Cost, Small, 4.5V to 28V Wide Operating
Range, DC-DC Synchronous Buck Controller
________________________________________________________________ Maxim Integrated Products 1
2
4
5
*EP
13
11
10
LX
DL
DRV
V CC
EN
LIM
MAX15026
1 + 14 DH IN
3 12 BST PGOOD
6 9 GND COMP
7 8 RT FB
TDFN
(3mm x 3mm)
TOP VIEW
*EP = EXPOSED PAD.
Pin Configuration
Ordering Information
19-4108; Rev 0; 5/08
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
EVALUATION KIT
AVAILABLE
PART TEMP RANGE PIN-PACKAGE
MAX15026BETD+ -40°C to +85°C 14 TDFN-EP*
+ Denotes a lead-free package.
* EP = Exposed pad.