FEATURES
 Power Supply Voltage VPS Range: 5V ∼ 14V
 Full Swing Output Voltage: 0.2VVPS to 0.8VVPS
(input voltage)
 Maximum Output Current: 4A
 High Efficiency: ≥90% - no heat sink is needed
(IOUT=4A@VLDA=10V & VVPS=14V)
 Wide Modulation Bandwidth: DC ∼ 4kHz
 Dual Independent Current Set Ports
 Direct Digital Modulation Control
 Three Control States: Shutdown, Standby and Operation
 Low Output Current Noise: 6.07μAP-P @0.1Hz~10Hz
 High Current Stability: < ±600μA@4A &‒20°C~80°C
 Low Output Ripple Voltage: < 6mV@500kHz
 Fully Shielded
 Both DIP and SMT Packages Available
 Compact Size: 27.4×21×5.7 (mm)
 100 % Lead (Pb)-free and RoHS Compliant
DESCRIPTION
This laser driver, ATLS4A214, 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 4mVpp
ripple voltage at 500kHz), 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 ~ 4kHz and low DC current drift make it ideal for driving
diode pumped single mode laser diodes to achieve mode-hopfree
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 ATLS4A214D.
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 ATLS4A214 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 500kHz