New Family Of Vacuum Fluorescent Display VFD Driver ICs From Cherry Semiconductor Offers Low Solution Cost For Automotive Instrumentation.

EAST GREENWICH, R.I.--(BUSINESS WIRE)--Aug. 19, 1999--

CS1084/85/86 Driver ICs Contain All the Circuitry

Needed to Interface Between a System Microprocessor

and Automotive VFD Instrumentation

Three new VFD driver ICs from Cherry Semiconductor Corporation reduce solution cost by eliminating excess circuitry in automotive instrumentation systems where the system microprocessor has sufficient pins to control driver ICs. The CS1084, CS1085, and CS1086 each contain a shift register, transparent data latches, a metal-mask read-only memory (ROM) and anode- and grid-drivers for controlling a multiplexed vacuum fluorescent display (VFD) cluster in an automotive instrument panel.

The CS1084 and CS1086 drivers each consist of a 32-bit shift register, 32-bit transparent data latch, a factory programmable metal-mask ROM, six 20 mA anode output drivers, twenty-three 2 mA anode output drivers and three 50 mA grid drivers. The ROM allows the 29 anode outputs and 3 grid outputs to be assigned to any of the 32 serial data bits that drive the display. Data is fed into the shift register serially through the Din (Data In) pin and stored in the 32 individual registers on the rising edge of the CLK (Clock) input. Once the register is loaded with the 32 data bits, they are transferred to the data latch by setting the STB (Standby) pin high. The ROM decodes the latch data and sends the specific bit pattern to the output drivers that feed the VFD.

The three grid outputs are gated by the GREN (Grid Outputs Enable) input. When GREN is low the grid outputs are forced low, and when GREN is high, the grid outputs correspond to the state of their respective latch outputs. The Dout pin, the last stage of the shift register, can be used to serially cascade a display driver chip to another device of the same type. The difference between the CS1084 and CS1086 is that the input bits address different output pins.

The CS1085 has a 34-bit shift register, 34-bit data latch, six 20 mA anode drivers, twenty five 2 mA drivers and three 50 mA grid drivers. It also contains a metal-mask ROM (factory programmable). Unlike the CS1084 and CS1086, the CS1085 does not include a Dout pin for cascading to other display drivers. In all other respects - operation, specifications and packaging - the devices are identical.

All three display drivers can operate from a supply voltage between 8V and 16.5V and accept logic input voltages (Din, CLK, STB, GREN) up to 6.0V. Features include power on reset and dimming of the display. Dimming is accomplished by pulse width modulation of the grids. The operating temperature range is -40(degree)C to 105(degree)C, with 1W maximum power dissipation at 105(degree)C. Other applications for the family include automotive audio/radio display clusters.

The CS1084/1085/1086 are supplied in three packaging options to accommodate a variety of printed circuit board designs: 40-lead plastic DIP (PDIP), 44-lead plastic chip carrier (PLCC) and 48-lead quad flat pack (LQFP).

In quantities of 10,000 pieces, all versions are priced at $2.75 each.

Data sheets and samples can be requested via the Cherry Semiconductor website at http://www.cherry-semi.com. Reference designs, demonstration kits and samples are available to qualified individuals through Cherry's local sales and applications personnel.