FEATURES
 Wide Input Voltage Range: 4.5V ∼15V
 Wide Output Voltage Range: 0.2VVPS to 0.8VVPS (input
voltage)
 Maximum Output Current: 2A
 High Efficiency: ≥92% - no heat sink is needed
(IOUT=2A@LDA=10V&VVPS =15V)
 Wide Modulation Bandwidth: DC ∼10kHz
 Dual Independent Current Set Ports: LISH and LISL
 Direct Digital Modulation Control: PCN
 Three Control States: Shutdown, Standby and Operation
 Low Output Current Noise: 4.39μAP-P @0.1Hz ~ 10Hz
 High Current Stability: <250μA@2A &−20°C ∼80°C
 Low Output Ripple Voltage: <4mV@500kHz
 Fully Shielded
 Compact Size: 25.4×20×5 (mm)
 100 % Lead (Pb)-free and RoHS Compliant
DESCRIPTION
This laser driver, ATLS2A212, is an electronic module that
has all the valuable and important, but often difficult to
achieve simultaneously, features: 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
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
2A 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 ATLS2A212D.
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 driver 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 ATLS2A212 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.