2
dc1987af
DEMO MANUAL DC1987A
Quick start proceDure
Demo circuit 1987A provides an easy method to evalu-
ate the performance of the LTM8057. Refer to Figure 3
for proper measurement equipment setup and follow the
procedure below:
NOTE. When measuring the input or output voltage ripple,
care must be taken to avoid a long ground lead on the
oscilloscope probe. Measure the input or output voltage
ripple by touching the probe tip directly across the VIN or
VOUT and GND terminals. See Figure 4 for proper scope
probe technique.
1. With power off, connect the input power supply to VIN
and GND.
2. Turn on the power at the input.
NOTE. Make sure that the input voltage does not
exceed 29V.
3. Check for the proper output voltage. (For V
OUT
, check
the voltage between VOUT and VOUT–)
NOTE. If there is no output, temporarily disconnect the
load to make sure that the load is not set too high.
4. Once the proper output voltages are established, adjust
the load within the operating range and observe the
output voltage regulation, ripple voltage, efficiency and
other parameters.
performance summary
Specifications are at T
A
= 25°C
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Minimum Input Voltage
4.5
V
Maximum Input Voltage
29
V
Output Voltage V
OUT
V
IN
= 4.5V – 29V
4.75
5.25
V
Voltage Ripple V
OUT
V
IN
= 12V, I
OUT
= 100mA
10
mV
