MAX1816 Datasheet, PDF (1/49 Pages) Maxim Integrated Products – Dual Step-Down Controllers Plus Linear- Regulator Controller for Notebook Computers

19-2569; Rev 0; 10/02
Dual Step-Down Controllers Plus Linear-
Regulator Controller for Notebook Computers
General Description
The MAX1816/MAX1994 are dual step-down controllers
for notebook computer applications. BUCK1 is a CPU
core regulator with dynamically adjustable output, ultra-
fast transient response, high DC accuracy, and high effi-
ciency. BUCK2 is an adjustable step-down regulator for
I/O and memory supplies. Both regulators employ Maxim’s
proprietary Quick-PWM™ control architecture. This fast-
response, constant-on-time PWM control scheme handles
wide input/output voltage ratios with ease and provides
100ns “instant” on-response to load transients, while main-
taining a relatively constant switching frequency. The
MAX1816/MAX1994 also have a linear-regulator controller
for low-voltage auxiliary power supplies.
The CPU regulator supports “active voltage positioning”
to reduce output bulk capacitance and lower power dis-
sipation. A programmable gain amplifier allows the use
of lower value sense resistors. Four fixed-gain settings
are available (0, 1.5, 2, and 4). A differential remote-
sense amplifier is also included to more accurately con-
trol the voltage at the load. Accuracy is further
enhanced with an internal integrator.
The MAX1816/MAX1994 include a specialized digital
interface that makes them suitable for mobile CPU and
video processor applications. The power-good
(PGOOD) output for the core regulator is forced high
during VID transitions, and the LINGOOD output for the
linear regulator includes a 1ms (min) turn-on delay.
BUCK1, BUCK2, and the linear regulator feature overvolt-
age protection (OVP). The detection threshold for BUCK1
is adjusted with an external resistive voltage-divider, while
the OVP thresholds for BUCK2 and the linear regulator
are fixed. Connecting the OVPSET pin to V_CC disables
OVP for BUCK1 and BUCK2, but not the linear regulator.
The MAX1816 features an output-voltage adjustment
range from 0.6V to 1.75V. Similarly, the MAX1994 is
adjustable from 0.925V to 2.0V, using an alternate VID
code set. While in suspend mode, the adjustment range
is 0.7V to 1.075V for both the MAX1816 and MAX1994.
Both parts are available in 48-pin thin QFN packages.
Applications
Mobile CPU Core and Video Processors
Memory I/O and VID Supplies
3- to 4-Cell Li+ Battery to CPU Core Supply
Small Notebook Computers
Features
o Dual Quick-PWM Architecture
o ±1% V_OUT Accuracy
o 5-Bit On-Board D/A Converter
o +0.60V to +1.75V Output Adjust Range (MAX1816)
o +0.70V to +2.00V Output Adjust Range (MAX1994)
o Voltage-Positioning Gain and Offset Control
o +2V to +28V Battery Input Range
o Differential Remote Sense (BUCK1)
o Linear-Regulator Controller
o 200/300/550/1000kHz Switching Frequency
o 2.2mA (typ) I_CC Supply Current
o 20µA (max) Shutdown Supply Current
o Independent Power-Good Outputs
(PGOOD, LINGOOD)
PART
MAX1816ETM
MAX1994ETM
Ordering Information
TEMP RANGE
-40°C to +100°C
-40°C to +100°C
PIN-PACKAGE
48 Thin QFN
48 Thin QFN
Pin Configuration
TOP VIEW
ILIM1 1
CC 2
CS1+ 3
CS1- 4
FBS 5
GDS 6
GAIN 7
OFS0 8
OFS1 9
OFS2 10
SUS 11
DPSLP 12
MAX1816
MAX1994
36 ILIM2
35 CS2
34 OUT2
33 FB2
32 REF
31 V_CC
30 AGND
29 LINBSE
28 LINGOOD
27 LINFB
26 TIME
25 OVPSET
Quick-PWM is a trademark of Maxim Integrated Products, Inc.
THIN QFN 7mm × 7mm
________________________________________________________________ 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.