MAX15026 Datasheet, PDF (1/23 Pages) Maxim Integrated Products – Low-Cost, Small, 4.5V to 28V Wide Operating Range, DC-DC Synchronous Buck Controller

19-4108; Rev 1; 5/09
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Low-Cost, Small, 4.5V to 28V Wide Operating
Range, DC-DC Synchronous Buck Controller
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 extended -40°C
to +85°C and automotive -40°C to +125°C temperature
ranges.
Applications
Set-Top Boxes
LCD TV Secondary Supplies
Switches/Routers
Power Modules
DSP Power Supplies
Points-of-Load Regulators
Features
o 4.5V to 28V or 5V ±10% Input Supply Range
o 0.6V to (0.85 x V_IN) Adjustable Output
o Adjustable 200kHz to 2MHz Switching Frequency
o Ability to Start into a Prebiased Load
o Lossless, Cycle-by-Cycle Valley Mode Current
Limit with Adjustable, Temperature-Compensated
Threshold
o Sink-Mode Current-Limit Protection
o Adaptive Internal Digital Soft-Start
o ±1% Accurate Voltage Reference
o Internal Boost Diode
o Adaptive Synchronous Rectification Eliminates
External Freewheeling Schottky Diode
o Hiccup-Mode Short-Circuit Protection
o Thermal Shutdown
o Power-Good Output and Enable Input for Power
Sequencing
o ±5% Accurate Enable Input Threshold
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX15026BETD+ -40°C to +85°C
14 TDFN-EP*
MAX15026BATD+ -40°C to +125°C
14 TDFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Pin Configuration
TOP VIEW
IN 1
V_CC 2
PGOOD 3
EN 4
LIM 5
COMP 6
FB 7
+
MAX15026
*EP
14 DH
13 LX
12 BST
11 DL
10 DRV
9 GND
8 RT
*EP = EXPOSED PAD.
TDFN
(3mm x 3mm)
________________________________________________________________ Maxim Integrated Products 1
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.