GE Industrial Solutions NH020-Series - Manual (Page 10)

Lineage Power 10
Data Sheet
October 14, 2009
5 Vdc Input; 1.5 Vdc to 3.3 Vdc Output; 20 W
NH020-Series Power SIPs:
Feature Descriptions
Remote On/Off
To turn the power SIP on and off, the user must supply a
switch to control the voltage at the on/off terminal (Von/off).
The switch can be an open collector pnp transistor con-
nected between the on/off terminal and the VI terminal or its
equivalent (see Figure 20).
During a logic low when the ON/OFF pin is open, the power
SIP is on and the maximum Von/off generated
by the power SIP is 0.3 V. The maximum
allowable leakage current of the switch when
Von/off = 0.3 V and VI = 5.5 V (Vswitch = 5.2 V) is 50 µA.
During a logic high, when Von/off = 2.8 V to 5.5 V, the power
SIP is off and the maximum Ion/off is 10 mA. The switch
should maintain a logic high while sourcing 10 mA.
If not using the remote on/off feature, leave the
ON/OFF pin open.
The SIP has internal capacitance to reduce noise at the ON/
OFF pin. Additional capacitance is not generally needed and
may degrade the start-up characteristics of the SIP.
CAUTION: Never ground the on/off terminal. Ground-
ing the on/off terminal disables an impor-
tant safety feature and may damage the SIP
or the customer system.
Figure 20. Remote On/Off Implementation.
Output Voltage Set-Point Adjustment
(Trim)
Output voltage set-point adjustment allows the output volt-
age set point to be increased or decreased by connecting an
external resistor between the TRIM pin and either the VO pin
(decrease output voltage) or GND pin (increase output volt-
age). The trim range for the NH020F is +10%, –16%. The
trim range for the NH020G is ±10% of VO, nom. The trim
range for SIPs that produce less than 2.5 VO is +20%, –0%.
Connecting an external resistor (Rtrim-down) between the
TRIM and VO pin decreases the output voltage set point as
defined in the following equation.
For the F (3.3 VO) SIP:
For the G (2.5 VO) SIP:
Note: Output voltages below 2.5 V cannot be trimmed
down.
The test results for these configurations are displayed in Fig-
ures 21 and 22.
Figure 21. NH020G Rtrim-down Test Results .
Figure 22. NH020F Rtrim-down Test Results .
Connecting an external resistor (Rtrim-up) between the
TRIM and GND pins increases the output voltage set point
to VO, adj as defined in the following equation:
The test results for this configuration are displayed in Fig-
ures 23—26.
Leave the TRIM pin open if not using that feature.
R trim-down
18.23
V O V O adj , –
------------------------------ 15 – ⎝ ⎠
⎛ ⎞
k
Ω
=
R trim-down
6.975
2.498 V
O adj , –
------------------------------------- 15 – ⎝ ⎠
⎛ ⎞
k
Ω
=
R trim-up
28
V O adj , V O –
------------------------------ 1 – ⎝ ⎠
⎛ ⎞
k
Ω
=