MIC5400 Datasheet, PDF (1/10 Pages) Micrel Semiconductor – Dual, 8-Output, 14-Bit LED Video Display Driver

MIC5400
Micrel
MIC5400
Dual, 8-Output, 14-Bit LED Video Display Driver
General Description
The MIC5400 consists of 2 banks of 8 LED driver outputs,
each output capable of sinking up to 30mA. Each bank is
intended to drive 8 LED pixels of the same color. Most
applications will use the MIC5400 to drive pixel clusters of 4
LEDs (RRGB.) Typically two red LEDs are used for every one
green and blue to compensate for red LED brightness.
A single external resistor sets maximum drive current. Use of
an external resistor allows different color LED banks to be
biased to the same intensity. Brightness control is digitally
programmed through the serial interface. Coarse Brightness
Control is determined by two 4-bit DACs, one for each driver
bank, limiting the full-scale output to a fraction of the maxi-
mum value. Additionally, each output has Fine Brightness
Control using 10-bit resolution PWM.
Groups of drivers can be cascaded in Daisy Chain fashion.
Open circuit output faults are detected and can be read back
from the internal Status register.
Features
• 2 banks of 8 outputs
• Output characteristics:
• Current sink: 30mA
– Programmable brightness control
• Coarse: 4-bit resolution DAC
• Fine: 10-bit resolution PWM
– Resistor sets maximum LED current to compensate
variation in LEDs
– Current limit on each output
• Full protection:
– Over-temperature shutdown
– Watchdog disables output under fault condition
– Power-on reset (all LEDs Off)
– Soft-start on power up and watchdog recovery
– Output open fault detection with status register
readback
• Output transitions are staggered to minimize supply
transients
Applications
• Outdoor video screen
• Large LED display
Ordering Information
Part Number Junction Temp. Range
Package
MIC5400BWM
–40°C to +85°C
28-Pin Wide SOIC
Typical Application
R_SC
R_SET
MIC5400
VDDA
SHFTCLK
SHIFTIN
SHIFTOUT
LOAD
Logic
Control and
SRegister
Output A
BD_A
BCP69
2.2µF
330½
BCP69
2.2µF
330½
V_DD
0.01µF
VDD
Output B
BD_B
VDDB
R_SC
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com
November 2002
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MIC5400