Microchip Technology HV881K7-G

Description
The Supertex HV881 is a 16-channel EL lamp driver with a single common terminal. It can drive up to a 1nF EL lamp load on each of the sixteen channels. The input supply voltage range is 1.8 to 5.5V, and the logic interface to the device can be as low as 1.7V. The device has an enable logic input pin to turn the device on or off.
The HV881 uses an external MOSFET, a single inductor, and a minimum number of passive components to drive all sixteen EL lamps. The device is designed such that the input voltage to the inductor can be different from the input voltage to the device (split supply).
The HV881 has two internal oscillators and a high-voltage EL lamp driver. An external MOSFET is driven by the switch oscillator to generate output voltage. The frequency for the external switching MOSFET is set by an external resistor connected between the RSW-Osc pin and the VDD supply pin. The EL lamp driver frequency can be set by either an external logic signal frequency at the SEL pin or by an external resistor connected between the REL-Osc pin and VDD pin.
An external inductor is connected between the LX and VDD or VIN pins for split supply applications. Depending on the EL lamp sizes, a 1.0 to 10.0nF capacitor is connected between the CS pin and ground. The CS capacitor is connected to the internal H-bridge, and the energy stored in the capacitor is therefore transferred to the EL lamp.
One side of all the sixteen EL lamps is connected to the respective EL pins (EL1, EL2, etc.), and the other side is connected to the COM pin.
The external switching MOSFET charges the inductor and discharges it into the capacitor at CS. The voltage at CS will start to increase. Once the voltage at CS reaches the desired regulation limit, the external switching MOSFET is turned off to conserve power.
The HV881 allows for controlling the fall time of the EL1-EL16 outputs by an external resistor from the RSLOPE pin to the VDD pin. This feature can be used to reduce the audible noise of the EL lamp or to increase the lamp brightness.
The brightness of each of the sixteen EL lamps can be independently controlled to have one of fifteen brightness levels or can be completely turned off by the serial data (SDA) input. The serial data input has a 4-bit binary code for each lamp, to control the brightness level from level 0 to level 15. The brightness is controlled by controlling the number of EL frequency cycles (from 0 to 15) in a group of 15 cycles.

Features
Sixteen channel EL lamp driver with single common terminal
1nF maximum load on each of the sixteen channels
Independent dimming capability for all lamps
Sixteen brightness levels for each lamp
1.8 to 5.5V operating supply range
1.7V logic interface
Dedicated enable logic pin
340V nominal output voltage for high brightness
Low audible noise
Output voltage regulation
EL1 - EL 16 outputs fall time control
Two EL frequency controls
External switching MOSFET
1ºC data communication control
Single lithium-ion cell compatible
One miniature inductor to power sixteen lamps
Independent lamp and converter frequency setting
Split supply capability
5x5mm, 32-Lead QFN package

Applications
Multi-segment, variable displays
Cell phone keypads and displays
Multi-segment remote controls
Handheld wireless communication products
Global Positioning Systems (GPS)