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.