MIC4826_09 Datasheet, PDF (1/12 Pages) Micrel Semiconductor – Low Input Voltage, 160VPP Output Voltage, EL Driver

MIC4826
Micrel
MIC4826
Low Input Voltage, 160V_PP Output Voltage, EL Driver
General Description
Micrel’s MIC4826 is a high output voltage, DC to AC converter,
designed for driving EL (Electroluminescent) lamps. The
device operates from an input voltage range of 1.8V to 5.5V,
making it suitable for 1-cell Li Ion and 2- or 3-cell alkaline/
NiCad/NiMH battery applications. The MIC4826 converts
a low voltage DC input to a 160V_PP AC output signal that
drives the EL lamp.
The MIC4826 is comprised of two stages: a boost stage, and
an H-bridge, lamp driver, stage. The boost stage steps the
input voltage up to +80V. The H-bridge stage then alternately
switches the +80V output to each terminal of the EL lamp,
thus creating a 160V_PP AC signal to drive the EL lamp and
generate light.
The MIC4826 features separate oscillators for the boost-
and H-bridge stages. External resistors independently set
the operating frequency of each stage. This flexibility allows
the EL lamp circuit to be optimized for maximum efficiency
and brightness.
The MIC4826 uses a single inductor and a minimum number
of external components, making it ideal for portable, space-
sensitive applications.
The MIC4826 is available in an 8-pin MSOP package with
an ambient temperature range of –40°C to +85°C.
Features
• 1.8V to 5.5V DC input voltage
• 160V_PP regulated AC output waveform
• Independently adjustable EL lamp frequency
• Independently adjustable boost converter frequency
• 0.1µA shutdown current
Applications
• LCD panel backlight
• Cellular phones
• PDAs
• Pagers
• Calculators
• Remote controls
• Portable phones
Ordering Information
Part Number
Standard Pb-Free
MIC4826BMM MIC4826YMM
Temp. Range
–40°C to +85°C
Package
MSOP-8
Typical Application
V_IN
C_IN
10µF
L1
220µH
D1
BAV19WS
442k
2M
MIC4826
1 _VDD
2 _RSW
3 _REL
4 _GND
SW ⁵
CS ⁶
VA ⁸
VB ⁷
C_OUT
0.01µF/100V
2in² EL LAMP
High Voltage EL Driver
TIME (2ms/div)
V_IN = 3.0V
L = 220µH�
LCa^Om^UTp==02.0in1^2µ�^F
R_SW = 332k�
R_EL = 3.32M
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com
March 2009
1
MIC4826