FEATURES

 Wide Input Voltage Range: 5.5V ∼ 27V

 Wide Output Voltage Range: 0.2VVPS to 0.8VVPS

(input voltage)

 High Current Capability: 4A

 High Efficiency: ≥90

(IOUT=4A@VLDA=20V&VVPS=27V)

 Wide Modulation Bandwidth: DC ∼ 10kHz

 Compact Size: 27.4×21×5.7 (mm)

 Dual Independent Current Set Ports: LISH and LISL

 Direct Digital Modulation Control: PCN

 Three Control States: Shutdown, Standby and Operation

 Low Output Current Noise: < 12μAP-P@0.1Hz~10Hz

 High Current Stability: < ±600μA@4A &‒20°C~80°C

 Low Output Ripple Voltage: < 6mV@700kHz

 Fully Shielded

 100 Lead (Pb)-free and RoHS Compliant

DESCRIPTION

This laser driver, ATLS4A217, is an electronic module that

has all the valuable and important, but often difficult to

achieve simultaneously, features simultaneously: wide input

and output voltage range, high output current capability, high

efficiency, low output noise (but it has an output 4mVp-p

ripple voltage at 700kHz), wide modulation bandwidth, and

small size. The wide output voltage range, 0.2VVPS ~ 0.8VVPS,

allows driving one or multiple serial laser diodes at the same

time, for up to 4A well controlled current at high efficiency.

The extremely low noise between DC ~ 10kHz and low DC

current drift make it ideal for driving diode pumped single mode

laser diodes to achieve mode-hop-free and narrow optical

wavelength drift, thus, long coherent length. Because of the high

efficiency, the laser driver generates small amount of heat, thus,

no heat sink is necessary for normal operation. The fully

shielded case blocks all the incoming and outgoing EMIs

(Electro-Magnet Interferences). Therefore, this laser will not

interfere other surrounding electronics, nor will be interfered by

them. The small package saves valuable PCB space in laser

systems. Figure 1 shows physical photo of the ATLS4A217D.

This laser driver has two current set ports digitally controlled to

switch between them for setting the output current. This feature

allows modulating the laser digitally with 2 preset current values.

The actual laser current and laser driver temperature are

monitored by dedicated ports. In case the laser driver

temperature exceeds the limit, 120°C, the laser driver will shut

down the output stage by itself and force the laser drive into

Standby Mode. There is a loop good indication output to tell if

the laser driver works ok.

The laser driver has 3 states: Operation, Standby and Shutdown.

Under Standby mode, all the laser driver components works

except the output stage, see Figure 4. Under Shutdown mode, all

the components of the laser driver stops working and the power

supply current is reduced to < 3μA.

This laser driver generates a high accuracy high stability low

noise, 5μVP-P, < 1μVRMS, < 8ppm/°C, 2.5V<±2mV, voltage

reference output which can be used for setting the output current

and also be used as the reference voltage for the ADCs (Analog

to Digital Converters)and/or DACs (Digital to Analog

Converters).

The ATLS4A217 uses a constant frequency high efficiency

PWM output stage. Its switching signal is taken out through a

buffer at the SYNO port, pin 14, which can be used by other

switch mode electronics as the trigger signal to avoid frequency

beating interference, if the free-run frequency is around 700kHz.