MCW1000 Series
Test Configurations
Input Reflected-Ripple Current Test Setup
Input reflected-ripple current is measured with a inductor
Lin (4.7uH) and Cin (220uF, ESR < 1.0[ at 100 KHz) to
simulate source impedance.
Capacitor Cin, offsets possible battery impedance.
Current ripple is measured at the input terminals of the
module, measurement bandwidth is 0-500 KHz.
To Oscilloscope
+
Battery
+
Lin
Current
Probe
+Vin
+Out
Load
Maximum Capacitive Load
The MCW1000 series has limitation of maximum
connected capacitance at the output.
The power module may be operated in current limiting
mode during start-up, affecting the ramp-up and the startup
time.
The maximum capacitance can be found in the data sheet.
Overcurrent Protection
To provide protection in a fault (output overload) condition,
the unit is equipped with internal current limiting circuitry and
can endure current limiting for an unlimited duration. At the
point of current-limit inception, the unit shifts from voltage
control to current control. The unit operates normally once the
output current is brought back into its specified range.
DC / DC
Converter
-Vin
-Out
Cin
Input Source Impedance
Peak-to-Peak Output Noise Measurement Test
Use a Cout 0.47uF ceramic capacitor.
Scope measurement should be made by using a BNC
socket, measurement bandwidth is 0-20 MHz. Position the
load between 50 mm and 75 mm from the DC/DC Converter.
+Vin
Single Output
DC / DC
Converter
-Vin
-Out
+Out
Copper Strip
Cout
Scope
Resistive
Load
The power module should be connected to a low
ac-impedance input source. Highly inductive source
impedances can affect the stability of the power module.
In applications where power is supplied over long lines and
output loading is high, it may be necessary to use a capacitor
at the input to ensure startup.
Capacitor mounted close to the power module helps
ensure stability of the unit, it is recommended to use a good
quality low Equivalent Series Resistance (ESR < 1.0[ at 100
KHz) capacitor of a 8.2uF for the 5V input devices, a 3.3uF for
the 12V input devices and a 1.5uF for the 24V and 48V
devices.
+
+Vin
+
Cin
-Vin
-Out
DC / DC
Converter
+Out
Load
Design & Feature Considerations
Remote On/Off
Positive logic remote on/off turns the module on during a
logic high voltage on the remote on/off pin, and off during a
logic low.
To turn the power module on and off, the user must supply
a switch to control the voltage between the on/off terminal and
the -Vin terminal.
The switch can be an open collector or equivalent.
A logic low is 2.7V to 15V.
A logic high is under 0.6 VDC or open circuit, drops down
to 0VDC by 2mV/]
The maximum sink current at on/off terminal during a logic
low is 1 mA.
The maximum allowable leakage current of the switch at
on/off terminal (under 0.6VDC or open circuit) is -0.4mA.
DC Power
Source
-
Output Ripple Reduction
A good quality low ESR capacitor placed as close as
practicable across the load will give the best ripple and noise
performance.
To reduce output ripple, it is recommended to use 3.3uF
capacitors at the output.
+
DC Power
Source
-
+Vin
Single Output
DC / DC
Converter
-Vin
+Out
Cout
-Out
Load
REV:0 2005/04
MINMAX
6
MINMAX [ MINMAX TECHNOLOGY CO., LTD. ]
