HW006/010/012 Series Power Modules; dc-dc Converters
36-75 Vdc Input; 1.2 Vdc to 5 Vdc Output; 6.6A to 12A
Data Sheet
June 26, 2009
Feature Descriptions (continued)
VI(+)
VO(+)
Output Voltage Set-Point Adjustment
Rtrim-up
(Trim) (continued)
ON/OFF
RLOAD
TRIM
VO(–)
VI(–)
VI(+)
VO(+)
ON/OFF
TRIM
VO(–)
RLOAD
Figure 42. Circuit Configuration to Increase
Output Voltage.
VI(–)
Rtrim-down
The amount of power delivered by the module is defined as
the voltage at the output terminals multiplied by the output
current. When using trim, the output voltage of the module
can be increased, which at the same output current would
increase the power output of the module. Care should be
taken to ensure that the maximum output power of the mod-
ule remains at or below the maximum rated power (maxi-
mum rated power = VO, set x IO, max).
Figure 41. Circuit Configuration to Decrease Output
Voltage.
With an external resistor Rtrim-up, connected between the
TRIM and VO(+) pins, the output voltage set point VO, set
increases (see Fiugre 42). The following equation deter-
mines the required external-resistor value to trim-up the out-
put voltage from VO, set to VO:
Overcurrent Protection
To provide protection in an output overload fault condition,
the module is equipped with internal current-limiting circuitry,
and can endure current limiting for an unlimited duration. At
the instance of current-limit inception, the module enters a
"hiccup" mode of operation, whereby it shuts down and auto-
matically attempts to restart. While the fault condition exists,
the module will remain in this mode until the fault is cleared.
The unit operates normally once the output current is
reduced back into its specified range.
⎧
⎨
⎩
⎫
A(100 + Δ%) – B
R
=
------------------------------------------- – C kΩ
⎬
trim-up
Δ%
⎭
Rtrim-up is the external resistor in kW
D% is the % change in output voltage
A, B and C are defined in Table 2
Table 2
Output Overvoltage Protection
Output Voltage
A
B
C
(V)
The output overvoltage protection clamp consists of control
circuitry, independent of the primary regulation loop, that
monitors the voltage on the output terminals. This control
loop has a higher voltage set point than the primary loop
(See the overvoltage clamp values in the Feature Specifica-
tions Table). In a fault condition, the overvoltage clamp
ensures that the output voltage does not exceed VO, ovsd,
max. This provides a redundant voltage-control that reduces
the risk of output overvoltage.
1.2
1.5
1.8
2.5
3.3
5.0
15.9
19.8
23.8
34.5
45.5
69.0
1089
1089
1089
1690
1690
1690
62.0
104
104
73.1
73.1
73.1
For example, to trim-up the output voltage of 1.5 V module
(HW012A0M) by 8% to 1.62 V, Rtrim-up is calcualted is as
follows:
D% = 8
A = 19.8
B = 1089
C = 104
⎧
⎨
⎩
⎫
19.8(100 + 8) – 1089
R
R
=
--------------------------------------------------- – 104 kΩ
⎬
trim-up
trim-up
8
⎭
= 27.175kΩ
Lineage Power
14
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
