MAX1980 Datasheet, PDF (1/33 Pages) Maxim Integrated Products – Quick-PWM Slave Controller with Driver Disable for Multiphase DC-DC Converter

19-2298; Rev 2; 9/02
Quick-PWM Slave Controller with
Driver Disable for Multiphase DC-DC Converter
General Description
The MAX1980 step-down slave controller is intended for
low-voltage, high-current, multiphase DC-DC applica-
tions. The MAX1980 slave controller can be combined
with any of Maxim’s Quick-PWM^™ step-down controllers
to form a multiphase DC-DC converter. Existing Quick-
PWM controllers, such as the MAX1718, function as the
master controller, providing accurate output-voltage regu-
lation, fast transient response, and fault protection fea-
tures. Synchronized to the master’s low-side gate driver,
the MAX1980 includes the Quick-PWM constant on-time
controller, gate drivers for a synchronous rectifier, active
current balancing, and precision current-limit circuitry.
The MAX1980 provides the same high-efficiency, ultra-
low duty factor capability, and excellent transient
response as other Quick-PWM controllers. The MAX1980
differentially senses the inductor currents of both the
master and the slave across current-sense resistors.
These differential inputs and the adjustable current-limit
threshold derived from an external reference allow the
slave controller to accurately balance the inductor cur-
rents and provide precise current-limit protection. The
MAX1980’s dual-purpose current-limit input also allows
the slave controller to automatically enter a low-power
standby mode when the master controller shuts down.
The MAX1980 features a driver-disable mode that forces
both gate drivers (DL and DH) low. While the MAX1980’s
drivers are disabled, the master controller can operate in
low-power skip mode, improving light-load efficiency.
Additionally, the MAX1980 includes selectable trigger
polarity, allowing the slave controller to trigger on the ris-
ing (out-of-phase) or falling (in-phase) edge of the mas-
ter’s low-side gate driver. Out-of-phase operation
staggers the master and slave’s on-times, reducing the
input ripple current and consequently the number of
input capacitors. The MAX1980 also features a selec-
table 200kHz/300kHz/550kHz switching frequency. The
MAX1980 is available in compact 20-pin 5mm ✕ 5mm
QFN and thin QFN packages.
Applications
Notebook Computers
CPU Core Supply
Single-Stage (BATT to V_CORE) Converters
Two-Stage (5V to V_CORE) Converters
Servers/Desktop Computers
Features
o Quick-PWM Slave Controller
o Precise, Active Current Balance (±1.25mV )
o Driver Disable Improves Light Load Efficiency
o Accurate, Adjustable Current-Limit Threshold
o Optimized for Low-Output Voltages (≤ 2V)
o 4V to 28V Battery Input Range
o Selectable 200kHz/300kHz/550kHz Switching
Frequency
o Drive Large Synchronous-Rectifier MOSFETs
o 525µA (typ) I_CC Supply Current
o 20µA Standby Supply Current
o Compact 20-Pin 5mm ✕ 5mm QFN and Thin QFN
Packages
Ordering Information
PART
MAX1980EGP*
TEMP RANGE
-40°C to +100°C
MAX1980ETP -40°C to +100°C
*Contact factory for availability.
PIN-PACKAGE
20 QFN (5mm x 5mm)
20 Thin QFN
(5mm x 5mm)
Pin Configuration
TOP VIEW
20 19 18 17 16
CM+ 1
CM- 2
TON ₃
CS- 4
CS+ 5
MAX1980
15 LX
14 DH
13 ^DD
12 V_CC
11 VDD
6 7 8 9 10
QFN/THIN QFN
5mm x 5mm
Quick-PWM is a trademark of Maxim Integrated Products, Inc.
Typical Operating Circuit appears at end of data sheet.
________________________________________________________________ Maxim Integrated Products 1
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.