Performance Summary; Quick Start Procedure - Linear Technology DC1818A Demo Manual

DEMO MANUAL DC1818A

PERFORMANCE SUMMARY

PARAMETER
Minimum Input Voltage, V
Maximum Input Voltage, V
Regulator Output Voltage, V
Maximum Regulator Output Current, I
LDO1 Output Voltage, V
LDO2,3 Output Voltage, V
LDO4,5 Output Voltage, V
V Efficiency
OUT0
Switching Frequency

QUICK START PROCEDURE

Demo circuit 1818A is an easy way to evaluate the perfor-
mance of the LTM8001. Refer to Figure 1 for the proper
measurement equipment setup and follow the procedure
below:
NOTE: Do not hot-plug the V
voltages. The absolute maximum voltage on V
and hot-plugging a power supply through wire leads to
the demonstration circuit can cause the voltage on the
extremely low ESR ceramic input capacitor to ring to
twice its DC value. In order to protect the LTM8001, an
aluminum electrolytic capacitor with higher ESR is placed
at the input terminals. This may protect against some, but
not all, input transients due to a hot-plugged power supply.
See Application Note 88 for more details.
1. Place JP1 for BIAS123 in the INTERNAL 3.4V position.
NOTE: DC1818A includes an LTM8020 regulator to provide
3.4V bias voltages to the LDOs. The 3.4V bias supply can
be disconnected using jumper JP1 to allow an external
bias supply.
2
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CONDITIONS
IN
IN
I ≤ 5A, I
OUT0 OUT0 OUT1-5
ILIM = V , I
OUT0 REF
1mA ≤ I ≤ 700mA, R14 = 121k
OUT1 OUT1
V = V
OUT2,3 OUT2 OUT3
V = V
OUT4,5 OUT4 OUT5
V = 12V, I
IN OUT0
R7 = 118k
terminal at high input
IN
= 0A, R9 = 19.6k
= 0A
OUT1-5
, SET2 = SET3, 2mA ≤ I ≤ 1.8A, R17 = 54.9k
OUT2,3
, SET4 = SET5, 2mA ≤ I ≤ 1.5A, R19 = 45.3k
OUT4,5
= 2.5A, I = 0A
OUT1-5
2. Connect the power supply (with power off), loads, and
meters as shown in Figure 1.
3. After all connections are made, turn on the input power
and verify that V
V , V
OUT1
is 40V respectively.
IN
NOTE: If V
to make sure that the loads are not set too high. If V
V or V
OUT2,3
loaded by at least the LDO minimum load current of 1mA,
2mA and 2mA respectively.
4. Once the proper output voltages are established, adjust
each load within its operating range and observe the
output voltage regulation, ripple voltage, efficiency and
other parameters.
MIN TYP
36
1.72
5
1.16
1.04
0.86
84
350
is 1.8V and the output voltages for
OUT0
, and V are 1.2V, 1.1V, and 0.9V
OUT2,3 OUT4,5
is too low, temporarily disconnect the loads
OUT0
is too high, make sure the outputs are
OUT4,5
MAX UNITS
6 V
V
1.84 V
A
1.25 V
1.13 V
0.94 V
%
kHz
,
OUT1
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