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MIC4827 Datasheet, PDF (1/13 Pages) Micrel Semiconductor – Low Input Voltage, 180VPP Output Voltage, EL Driver | |||
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MIC4827
Micrel
MIC4827
Low Input Voltage, 180VPP Output Voltage, EL Driver
Final Information
General Description
Micrelâs MIC4827 is a high output voltage, DC to AC con-
verter, 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 MIC4827 con-
verts a low voltage DC input to a 180VPP AC output signal that
drives the EL lamp.
The MIC4827 is comprised of two stages: a boost stage, and
an H-bridge, lamp driver, stage. The boost stage steps the
input voltage up to +90V. The H-bridge stage then alternately
switches the +90V output to each terminal of the EL lamp,
thus creating a 180VPP AC signal to drive the EL lamp and
generate light.
The MIC4827 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 MIC4827 uses a single inductor and a minimum number
of external components, making it ideal for portable, space-
sensitive applications.
The MIC4827 is available in an 8-pin MSOP package with an
ambient temperature range of â40°C to +85°C.
Features
⢠1.8V to 5.5V DC input voltage
⢠180VPP 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
MIC4827BMM
Ambient Temp. Range
â40°C to +85°C
Package
MSOP-8
Typical Application
L1
VIN
220µH
D1
1N4148
CIN
10µF
MIC4827
1 VDD
332k
2
RSW
3.32M
3
REL
4
GND
SW 5
6
CS
8
VA
7
VB
COUT
0.033µF/100V
2in2 EL LAMP
High Voltage EL Driver
TIME (2ms/div)
Micrel, Inc. ⢠1849 Fortune Drive ⢠San Jose, CA 95131 ⢠USA ⢠tel + 1 (408) 944-0800 ⢠fax + 1 (408) 944-0970 ⢠http://www.micrel.com
September 2001
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MIC4827
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