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AS1110

Datasheet - D e t a i l e d D e s c r i p t i o n

8 Detailed Description

The AS1110 is designed to drive up to 16 LEDs through a fast serial interface and 16 constant-current output drivers.

Furthermore, the AS1110 provides diagnostics for detecting open- or shorted-LEDs, as well as over-temperature con-

ditions for LED display systems, especially LED traffic sign applications.

The AS1110 contains an 16-bit shift register and an 16-bit data register, which convert serial input data into parallel out-

put format. At AS1110 output stages, sixteen regulated current sinks are designed to provide uniform and constant cur-

rent with excellent matching between ports for driving LEDs within a wide range of forward voltage variations. External

output current is adjustable from 0.5 to 100mA using an external resistor for flexibility in controlling the brightness

intensity of LEDs. The AS1110 guarantees to endure 15V maximum at the outputs.

The serial interface is capable of operating at a minimum of 30 MHz, satisfying the requirements of high-volume data

transmission.

Using a multiplexed input/output technique, the AS1110 adds additional functionality to pins SDO, LD and OEN. These

pins provide highly useful functions (open- and shorted-LED detection, over-temperature detection), thus reducing pin

count. Over-temperature detection will work on-the-run, whereas the open- and shorted-LED detection can be used

on-the-run or in low-current diagnostic mode (see page 15).

Figure 8. Block Diagram

AS1110

REXT

OEN

CLK

SDI

LD

Current

Generators

Detailed

Error

Detection

16-Bit Data

Register

16-Bit Shift

Register

Temperature

Detection

16-Bit Open

Detection &

Error Register

16-Bit Short

Detection &

Error Register

Global

Error

Detection

SDO

Indicates 16 Bit Path

Control Logic