Owner's manual

General Description
The MAX5092A/MAX5092B/MAX5093A/MAX5093B low-
quiescent-current, low-dropout (LDO) regulators contain
simple boost preregulators operating at a high frequency.
The devices seamlessly provide a preset 3.3V
(MAX5092A/MAX5093A) or 5V (MAX5092B/MAX5093B)
LDO output voltage from an automotive cold-crank
through load-dump (3.5V to 80V) input voltage condi-
tions. The MAX5092_/MAX5093_ deliver up to 250mA
with excellent load and line regulation. During normal
operation, when the battery is healthy, the boost preregu-
lator is completely turned off, reducing quiescent current
to 65µA (typ). This makes the devices suitable for
always-on power supplies.
The buck-boost operation achieved by this combination
of LDO and boost preregulator offers the advantage of
using a single off-the-shelf inductor in place of the mul-
tiple-winding custom magnetics needed in typical sin-
gle-ended primary inductor converter (SEPIC) and
transformer-based flyback topologies. The high operat-
ing frequency of the boost regulator significantly
reduces component size. The MAX5092_ integrates a
blocking diode to further reduce the external compo-
nent count. The boost preregulator output voltage is
preset to 7V. Both LDO and boost output voltages are
programmable using external resistors. The boost pre-
regulator output voltage is adjustable up to 11V
(MAX5092_), or up to 12V (MAX5093_). The LDO output
voltage is adjustable from 1.5V to 9V (MAX5092_) or
from 1.5V to 10V (MAX5093_).
The devices feature a shutdown mode with 5µA (typ)
shutdown current, a HOLD input to implement a self-hold-
ing circuit, and a power-on-reset output (RESET) with an
externally programmable timeout period. Additional fea-
tures include output overload, short-circuit, and thermal
protection.
The MAX5092_/MAX5093_ are available in a thermally
enhanced, 16-pin 5mm x 5mm thin QFN package and can
dissipate up to 2.7W at +70°C on a multilayer PC board.
Applications
Automotive—Body Electronics
Automotive—ECU
Industrial
Features
Wide Operating Input Voltage Range: 3.5V to 72V
with a 4V Startup Voltage
LDO Output Regulates to 5V Seamlessly from an
Input Voltage of 3.5V to 72V
Up to 250mA Output Current
Preset 3.3V, 5V, or Externally Programmable LDO
Output Voltage from 1.5V to 9V (MAX5092_) or
from 1.5V to 10V (MAX5093_)
Preset 7V or Externally Programmable Boost
Output Voltage Up to 11V (MAX5092_) or Up to
12V (MAX5093_)
65µA Quiescent Current in LDO Mode (V
IN
8V)
5µA Shutdown Current
Power-On Reset (RESET) with Programmable
Timeout Period
Output Short-Circuit and Thermal Protection
TQFN Package Capable of Dissipating Up to 2.7W
at +70°C
MAX5092/MAX5093
4V to 72V Input LDOs with Boost Preregulator
________________________________________________________________
Maxim Integrated Products
1
15
16
14
13
6
5
7
EN
HOLD
8
IN
LX
BSOUT
PGND_BST
1
+
2
VL
4
12 11 9
CT
RESET
OUT
OUT_SENSE
SET
PGND_LDO
MAX5092_/
MAX5093_
SGND LX
3
10
BSFB
THIN QFN
(5mm x 5mm)
TOP VIEW
PART TEMP RANGE
PIN-
PACKAGE
PKG
CODE
MAX5092AATE+* -40°C to +125°C 16 TQFN-EP** T1655-3
MAX5092BATE+ -40°C to +125°C 16 TQFN-EP** T1655-3
MAX5093AATE+* -40°C to +125°C 16 TQFN-EP** T1655-3
MAX5093BATE+ -40°C to +125°C 16 TQFN-EP** T1655-3
Pin Configuration
Ordering Information
19-0659; Rev 0; 10/06
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
+
Denotes lead-free package.
*
Future product—contact factory for availability.
**
EP = Exposed pad.
Typical Operating Circuit and Selector Guide appear at end
of data sheet.
EVALUATION KIT
AVAILABLE

Summary of content (23 pages)