MAX6946 Datasheet, PDF (1/24 Pages) Maxim Integrated Products – 10-Port, Constant-Current LED Driver and I/O Expander with PWM Intensity Control

19-0598; Rev 3; 2/08
EVAALVUAAILTAIOBNLEKIT
10-Port, Constant-Current LED Driver and
I/O Expander with PWM Intensity Control
General Description
The MAX6946/MAX6947 I²C-/SMBus^TM-compatible,
serial-interfaced peripherals provide microprocessors
with 10 I/O ports rated to 7V.
Each port can be configured as a 2.5mA to 20mA con-
stant-current LED driver (static or PWM), a 1.25mA to
10mA constant-current LED driver (static or PWM), an
open-drain logic output, or an overvoltage-protected
Schmitt logic input.
Analog and switching LED intensity control includes indi-
vidual 8-bit PWM control per output, individual 1-bit ana-
log current control (half/full scale) per output, and a global
3-bit DAC current control that applies to all LED outputs.
The MAX6946/MAX6947 can stagger the PWM timing of
the 10-port outputs in consecutively phased 45° incre-
ments. Staggering the outputs spreads the PWM load
currents over time in eight steps, helping to even out
the power-supply current and reduce the RMS current.
For a similar part with an SPI^TM-/QSPI^TM-/ or MICROWIRE^TM-
compatible interface, refer to the MAX6966/MAX6967
data sheet.
Applications
Cellular Phones
Portable Equipment
RGB LED Drivers
LCD Backlights
Keypad Backlights
LED Status Indicators
Typical Operating Circuit
μC
SCL
SDA
*MAX6946 ONLY.
**MAX6947 ONLY.
+3.3V
V_DD
P0
SCL
P1
SDA ^MAX6946
P2
P3
OSC* ^{MAX6947 P4}
RST
P5
P6
P7
AD0**
P8
GND
P9
V_EXT = +5V
LOGIC INPUT
LOGIC INPUT
LOGIC INPUT
LOGIC INPUT
LOGIC INPUT
LOGIC INPUT
LOGIC INPUT
SMBus is a trademark of Intel Corp.
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
Features
♦ 2.25V to 3.6V Operation
♦ I/O Ports Default to High Impedance (LEDs Off)
on Power-Up
♦ I/O Port Inputs Are Overvoltage Protected to 7V
♦ I/O Port Outputs Are 7V-Rated Open-Drain, 10mA
or 20mA Constant-Current Static/PWM LED
Drivers, or Open-Drain Logic Outputs
♦ I/O Ports Support Hot Insertion
♦ Individual 8-Bit PWM Intensity Control for Each LED
♦ RST Input Clears Serial Interface and Can Exit
Shutdown (Warm Start)
♦ MAX6946 OSC Input Allows for External PWM
Clock Input
♦ MAX6947 AD0 Input Selects from Two Slave
Addresses
♦ Auto Ramp-Up Out of Shutdown, and Up to 4s
Hold-Off Before Ramp-Down into Shutdown
♦ 0.8µA (typ) Shutdown Current
♦ -40°C to +125°C Temperature Range
♦ Tiny WLP Package (4 x 4 Grid)
Ordering Information
PART
PIN-PACKAGE
PKG
CODE
MAX6946ATE+
16 TQFN-EP*
T1633-4
MAX6946CAWE+
16 WLP
W162B2-1
MAX6947ATE+
16 TQFN-EP*
T1633-4
+Denotes a lead-free package.
*EP = Exposed pad.
Note: All devices are specified over the -40°C to +125°C operating
temperature range..
Pin Configurations
TOP VIEW
MAX6946C
A1
A2
A3
A4
RST
VDD
SCL
SDA
B1
B2
B3
B4
P9
OSC
P1
P0
C1
C2
C3
C4
P8
P7
P3
P2
D1
D2
D3
D4
P6
P5
GND
P4
(BUMPS ON BOTTOM)
16-BUMP, 2.1mm x 2.1mm WLP
Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products 1
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.