Data Sheet
March 26, 2008
JHC/JHW350 Power Module; dc-dc Converter
18 – 36Vdc or 36 – 75Vdc Input; 28Vdc Output; 350W
⎛
28 *
(
100
+
5
)
(100
+
2 * 5)
⎞
−
R
adj
−
up
= ⎜
⎟
K
Ω
1.225 * 5
5
⎝
⎠
R
tadj-up
= 458kΩ
Feature Descriptions
(continued)
the module remains at or below the maximum rated
power.
Output Overvoltage Protection
The output overvoltage protection consists of circuitry
that monitors the voltage on the output terminals. If
the voltage on the output terminals exceeds the over
voltage protection threshold, then the module will
shutdown and latch off. The latch is reset by either
cycling the input power for one second or by toggling
the on/off signal for one second. The protection
mechanism is such that the unit can continue in this
condition until the fault is cleared.
Figure 18. Circuit Configuration to Decrease
Output Voltage.
Overtemperature Protection
These modules feature an overtemperature protection
circuit to safeguard against thermal damage. The
circuit shuts down the module when the maximum
case reference temperature is exceeded. The module
will restart automatically when the case temperature
cools below the overtemperature shutdown threshold.
Input Undervoltage Lockout
At input voltages below the input undervoltage lockout
limit, the module operation is disabled. The module
will begin to operate at an input voltage above the
undervoltage lockout turn-on threshold.
Figure 19. Circuit Configuration to Increase
Output Voltage.
Examples:
To trim down the output of a nominal 28V module
(JHW350R) to 26.6V
Δ
%
=
∆%
= 5
28
V
−
26.6
V
×
100
28
V
⎛
100
⎞
R
adj
−
down
= ⎜
−
2
⎟
K
Ω
⎝
5
⎠
R
adj-down
= 18 kΩ
To trim up the output of a nominal 28V module
(JHW350R) to 29.4V
Δ
%
=
Δ%
= 5
28
V
−
29.4
V
×
100
28
V
LINEAGE
POWER
11
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
