Huawei GAQ40S3V3B, Техническое руководство

Страница: 8 / 11

8
GLOBAL ENERGY EFFICIENCY SPECIALIST
Remote On/Off
Figure 15: various circuits for driving the On/Off pin
Logic
Enable On/Off Pin Level Status
Negative
logic Low level On
High level or left
open Off
Remote Sense
Output Voltage Trim
Trim Up
The relationship between R
adj-up
and V
out
:
V
in
(+)
On/Off
V
in
(
–)
V
out
(+)
Sense(+)
Trim
Sense(
–)
V
out
(
–)
R
adj-up
Load
) ( 2 . 10
510
225 . 1
) 100 ( 1 . 5
kohm
V
R
nom
up adj



 
   


100


 

nom
nom
up trim
V
V V
Figure 17: Configuration diagram for Trim up
The output voltage can be increased by installing
an external resistor between the Trim pin and the
Sense(+) pin.
1. If the Trim pin is not used, it should be left open.
2. Ensure that the actual output power does not exceed
the maximum output power when raising the voltage.
The output voltage can be adjusted according to
the trim range specification by using the Trim pin.
Trim Down
The output voltage can be decreased by installing
an external resistor between the Trim pin and the
Sense(
–) pin.
Figure 18: Configuration diagram for Trim down
The relationship between R
adj-down
and V
out
:
V
in
(+)
On/Off
V
in
(
–)
V
out
(+)
Sense(+)
Trim
Sense(
–)
V
out
(
–)
R
adj-down
Load
) ( 2 . 10
510
kohm R
down adj




100


 

nom
down trim nom
V
V V
Simple control
On/Off
V
in
(
–)
On/Off
V
in
(
–)
On/Off
V
in
(
–)
On/Off
V
in
(
–)
Transistor control
Isolation control Direct logic drive
VCC
TTL/
COMS
GAQ40S3V3B
DC-DC Converter Technical Manual V1.4
Figure 16: Configuration diagram for remote sense
This function is used to compensate for voltage
drops on R
w
. The Sense(+), Sense(
–), V
out
(+), and
V
out
(
–) terminals should meet the following
requirements:
V
in
(+)
On/Off
V
in
(
–)
V
out
(+)
Sense(+)
Trim
Sense(
–)
V
out
(
–)
R
w
Load
R
w
R
w
indicates the line impedance between the output terminal
and the load.
If the remote sense function is disabled, the
Sense(+) terminal directly connects to the V
out
(+)
terminal and the Sense(
–) terminal directly
connects to the V
out
(
–) terminal.
[V
out
(+)
– V
out
(
–)] – [Sense(+) – Sense(–)] ≤ 10% x V
nom
(V
nom
is the rated output voltage.)