12-Bit High Output Current Source

ADN8810

Rev. 0

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FEATURES

High precision 12-bit current source

Low noise

Long term stability

Current output from 0 mA to 300 mA

Output fault indication

Low drift

Programmable maximum current

24-lead 4 mm × 4 mm leadframe chip scale package

3-wire serial interface

APPLICATIONS

Tunable laser current source

Programmable high output current source

Automatic test equipment

GENERAL DESCRIPTION

The ADN8810 is a 12-bit current source with an adjustable

full-scale output current of up to 300 mA. The full-scale out-

put current is set with two external sense resistors. The output

compliance voltage is 2.5 V, even at output currents up to

300 mA.

The device is particularly suited for tunable laser control and

can drive tunable laser front mirror, back mirror, phase, gain,

and amplification sections. A host CPU or microcontroller

controls the operation of the ADN8810 over a 3-wire SPI®

interface. The 3-bit address allows up to eight devices to be

independently controlled while attached to the same SPI bus.

The ADN8810 is guaranteed with ± 4 LSB INL and ± 0.75 LSB

DNL. Noise and digital feedthrough are kept low to ensure low

jitter operation for laser diode applications. Full-scale and

scaled output currents are given in Equations 1 and 2,

respectively.

SN

REF

FS

R

V

I

×

≈

10

(1)

⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛

+

×

×

×

=

1

.

0

15

1

4096

k

R

R

V

Code

I

SN

SN

REF

OUT

(2)

FUNCTIONAL BLOCK DIAGRAM

RESET

RESET

ENCOMP

FB

DVDD

AVDD

PVDD

5V

5V

3.3V

4.096V

VREF

CS

SERIAL

INTERFACE

SCLK

SDI

ADDRESS

ADDR0-2

IOUT

1.6V

1.6V

D1

ADN8810

FAULT

SB

AVSS DVSS DGND

SB

FAULT

INDICATION

3

Figure 1.