QM48T45 Family DC-DC Converter Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 45 A Output
Operations
of ≤ 0.8 V. An external voltage source (±20 V
maximum) may be connected directly to the ON/OFF
input, in which case it must be capable of sourcing or
Input and Output Impedance
These power converters have been designed to be
stable with no external capacitors when used in low
inductance input and output circuits.
sinking up to 1 mA depending on the signal polarity.
See the Startup Information section for system timing
waveforms associated with use of the ON/OFF pin.
In many applications, the inductance associated with
the distribution from the power source to the input of
the converter can affect the stability of the converter.
The addition of a 33 µF electrolytic capacitor with an
ESR < 1 ꢀ across the input helps to ensure stability
of the converter. In many applications, the user has
to use decoupling capacitance at the load. The
power converter will exhibit stable operation with
external load capacitance up to 40,000 µF on
3.3-1.0 V outputs.
Remote Sense (Pins 5 and 7)
The remote sense feature of the converter
compensates for voltage drops occurring between the
output pins of the converter and the load. The
SENSE(-) (Pin 5) and SENSE(+) (Pin 7) pins should
be connected at the load or at the point where
regulation is required (see Fig. B).
TM
Rw
Series
QmaX
Vout(+)
Vin(+)
ON/OFF
Vin(-)
Converter
100
SENSE(+)
(Top View)
Additionally, see the EMC section of this data sheet
for discussion of other external components which
may be required for control of conducted emissions.
Rload
TRIM
Vin
SENSE(-)
10
Vout(-)
Rw
ON/OFF (Pin 2)
Fig. B: Remote sense circuit configuration.
The ON/OFF pin is used to turn the power converter
on or off remotely via a system signal. There are two
remote control options available, positive logic and
negative logic, with both referenced to Vin(-). A
typical connection is shown in Fig. A.
CAUTION
If remote sensing is not utilized, the SENSE(-) pin must be
connected to the Vout(-) pin (Pin 4), and the SENSE(+) pin must
be connected to the Vout(+) pin (Pin 8) to ensure the converter will
regulate at the specified output voltage. If these connections are not
made, the converter will deliver an output voltage that is slightly
higher than the specified data sheet value.
TM Series
QmaX
Vin(+)
ON/OFF
Vin(-)
Vout(+)
SENSE(+)
TRIM
Converter
(Top View)
Rload
Vin
Because the sense leads carry minimal current, large
traces on the end-user board are not required.
However, sense traces should be run side by side and
located close to a ground plane to minimize system
noise and ensure optimum performance.
SENSE(-)
Vout(-)
CONTROL
INPUT
Fig. A: Circuit configuration for ON/OFF function.
The converter’s output overvoltage protection (OVP)
senses the voltage across Vout(+) and Vout(-), and
not across the sense lines, so the resistance (and
resulting voltage drop) between the output pins of the
converter and the load should be minimized to
prevent unwanted triggering of the OVP.
The positive logic version turns on when the ON/OFF
pin is at a logic high and turns off when at a logic low.
The converter is on when the ON/OFF pin is left
open. See the Electrical Specifications for logic
high/low definitions.
The negative logic version turns on when the pin is at
a logic low and turns off when the pin is at a logic
high. The ON/OFF pin can be hardwired directly to
Vin(-) to enable automatic power up of the converter
without the need of an external control signal
When utilizing the remote sense feature, care must be
taken not to exceed the maximum allowable output
power capability of the converter, which is equal to the
product of the nominal output voltage and the
allowable output current for the given conditions.
The ON/OFF pin is internally pulled up to 5 V through
a resistor. A properly debounced mechanical switch,
open-collector transistor, or FET can be used to drive
the input of the ON/OFF pin. The device must be
capable of sinking up to 0.2 mA at a low level voltage
When using remote sense, the output voltage at the
converter can be increased by as much as 10%
above the nominal rating in order to maintain the
required voltage across the load. Therefore, the
designer must, if necessary, decrease the maximum
MCD10073 Rev. 1.0
Page 3 of 36
www.power-one.com
5秒后页面跳转
压敏电阻器在直流电路中的过压保护应用探讨
电感耐压值及其与电感大小的关系
CNY17F光耦合器：特性、应用、封装、引脚功能及替换型号解析
DS1307资料解析：特性、引脚说明、替代推荐
微信公众号
抖音公众号
浙公网安备 33010502006866号 浙ICP备10014259号-119
营业执照ICP证
数据手册
如果您发现信息不准确，
