Rainbow Electronics MAX5098A - Manual

General Description
The MAX5098A is a dual-output, high-switching-frequen-
cy DC-DC converter with integrated n-channel switches
that can be used either in high-side or low-side configura-
tion. Each output can be configured either as a buck con-
verter or a boost converter. In the buck configuration, this
device delivers up to 2A from converter 1 and 1A from
converter 2. The MAX5098A also integrates a load-dump
protection circuitry that is capable of handling load-dump
transients up to 80V for automotive applications. The
load-dump protection circuit utilizes an internal charge-
pump to drive the gate of an external n-channel MOSFET.
When an overvoltage or load-dump condition occurs, the
series protection MOSFET absorbs the high voltage tran-
sient to prevent damage to lower voltage components.
The DC-DC converters operate over a wide operating
voltage range from 4.5V to 19V. The MAX5098A oper-
ates 180° out-of-phase with an adjustable switching fre-
quency to minimize external components while allowing
the ability to make trade-offs between the size, efficiency,
and cost. The high switching frequency (up to 2.2MHz)
also allows this device to operate outside the AM band
for automotive applications.
This device utilizes voltage-mode control for stable oper-
ation and external compensation, thus the loop gain is
tailored to optimize component selection and transient
response. This device can be synchronized to an exter-
nal clock fed at the SYNC input. Also, a clock output
(CKO) allows a master-slave connection of two devices
with a four-phase synchronized switching sequence.
Additional features include internal digital soft-start, indi-
vidual enable for each DC-DC regulator (EN1 and EN2),
open-drain power-good outputs (PGOOD1 and
PGOOD2), and a shutdown input (ON/OFF).
Other features of the MAX5098A include overvoltage pro-
tection, short-circuit (hiccup current limit) and thermal
protection. The MAX5098A is available in a thermally
enhanced, exposed pad, 5mm x 5mm, 32-pin TQFN
package and is fully specified over the automotive
-40°C to +125°C temperature range.
Applications
Automotive AM/FM Radio Power Supply
Automotive Instrument Cluster Display
Features
♦ Wide 4.5V to 5.5V or 5.2V to 19V Input Voltage
Range (with Up to 80V Load-Dump Protection)
♦ Dual-Output DC-DC Converter with Integrated
Power MOSFETs
♦ Each Output Configurable in Buck or Boost Mode
♦ Adjustable Outputs from 0.8V to 0.85V
IN Buck
Configuration) and from V IN to 28V (Boost
Configuration)
♦ I
OUT1 and I OUT2 of 2A and 1A (Respectively) in
Buck Configuration
♦ Switching Frequency Programmable from 200kHz
to 2.2MHz
♦ Synchronization Input (SYNC)
♦ Clock Output (CKO) for Four-Phase Master-Slave
Operation
♦ Individual Converter Enable Input and Power-
Good Output
♦ Low-I
Q (7µA) Standby Current (ON/OFF)
♦ Internal Digital Soft-Start and Soft-Stop
♦ Short-Circuit Protection on Outputs and
Maximum Duty-Cycle Limit
♦ Overvoltage Protection on Outputs with Auto
Restart
♦ Thermal Shutdown
♦ Thermally Enhanced 32-Pin TQFN Package
Dissipates up to 2.7W at +70°C
MAX5098A
Dual, 2.2MHz, Automotive Buck or Boost
Converter with 80V Load-Dump Protection
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
19-4111; 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.
Pin Configuration appears at end of data sheet
EVALUATION KIT
AVAILABLE
+ Denotes a lead-free package.
* EP = Exposed pad.
PART TEMP RANGE PIN-PACKAGE
MAX5098AATJ+ -40°C to +125°C 32 TQFN-EP*