Rainbow Electronics MAX17000 - Manual

General Description
The MAX17000 pulse-width modulation (PWM) con-
troller provides a complete power solution for notebook
DDR, DDR2, and DDR3 memory. It comprises a step-
down controller, a source-sink LDO regulator, and a ref-
erence buffer to generate the required VDDQ, VTT, and
VTTR rails.
The VDDQ rail is supplied by a step-down converter
using Maxim’s proprietary Quick-PWM™ controller. The
high-efficiency, constant-on-time PWM controller han-
dles wide input/output voltage ratios (low duty-cycle
applications) with ease and provides 100ns response
to load transients while maintaining a relatively constant
switching frequency. The Quick-PWM architecture cir-
cumvents the poor load-transient timing problems of
fixed-frequency current-mode PWMs while also avoid-
ing the problems caused by widely varying switching
frequencies in conventional constant-on-time and con-
stant-off-time PWM schemes. The controller senses the
current to achieve an accurate valley current-limit pro-
tection. It is also built in with overvoltage, undervoltage,
and thermal protections. The MAX17000 can be set to
run in three different modes: power-efficient SKIP
mode, low-noise forced-PWM mode, and standby
mode to support memory in notebook computer stand-
by operation. The switching frequency is programma-
ble from 200kHz to 600kHz to allow small components
and high efficiency. The VDDQ output voltage can be
set to a preset 1.8V or 1.5V, or be adjusted from 1.0V to
2.5V by an external resistor-divider. This output has 1%
accuracy over line-and-load operating range.
The MAX17000 includes a ±2A source-sink LDO regu-
lator for the memory termination VTT rail. This VTT regu-
lator has a ±5mV deadband that either sources or
sinks, ideal for the fast-changing load burst present in
memory termination applications. This feature also
reduces output capacitance requirements.
The VTTR reference buffer sources and sinks ±3mA,
providing the reference voltage needed by the memory
controller and devices on the memory bus.
The MAX17000 is available in a 24-pin, 4mm x 4mm,
Thin QFN package.
Applications
Notebook Computers
DDR, DDR2, and DDR3 Memory Supplies
SSTL Memory Supplies
Features
♦ SMPS Regulator (VDDQ)
Quick-PWM with 100ns Load-Step Response
Output Voltages—Preset 1.8V, 1.5V, or
Adjustable 1.0V to 2.5V
1% V OUT Accuracy Over Line and Load
26V Maximum Input Voltage Rating
Accurate Valley Current-Limit Protection
200kHz to 600kHz Switching Frequency
♦ Source/Sink Linear Regulator (VTT)
±2A Peak Source/Sink
Low-Output Capacitance Requirement
Output Voltages-Preset VDDQ/2 or REFIN
Adjustable from 0.5V to 1.5V
♦ Low Quiescent Current Standby State
♦ Soft-Start/Soft-Shutdown
♦ SMPS Power-Good Window Comparator
♦ VTT Power-Good Window Comparator
♦ Selectable Overvoltage Protection
♦ Undervoltage/Thermal Protections
♦ ±3mA Reference Buffer (VTTR)
MAX17000
Complete DDR2 and DDR3 Memory
Power-Management Solution
________________________________________________________________ Maxim Integrated Products 1
23
24
22
21
8
7
9
PGOOD1
VTTS VTTR
10
OVP
BST DH TON DL CSH
1 2
SKIP
4 5 6
17 18 16 14 13
V CC
SHDN
REFIN
VTTI
VTT
PGND2
MAX17000ETG+
PGOOD2
LX
3
15
AGND
20 11 FB PGND1
19 12 CSL V DD
THIN QFN
4mm x 4mm
TOP VIEW
STDBY
Pin Configuration
Ordering Information
19-4125; 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.
+ Denotes a lead-free package.
PART TEMP RANGE PIN-PACKAGE
MAX17000ETG+ -40°C to +85°C 24 Thin QFN
Quick-PWM is a trademark of Maxim Integrated Products, Inc.