EN5360DC ENPIRION [Enpirion, Inc.], EN5360DC Datasheet - Page 7

• Manufacturer Part Number: EN5360DC
• Description: 6A Voltage Mode Synchronous Buck PWM DC-DC Converter
• Manufacturer: ENPIRION [Enpirion, Inc.]

Rev 1.0 – July 2005
NOTES:
Theory of Operation
Synchronous Buck Converter
The EN5360 is a synchronous, pin programmable
power supply with integrated power MOSFET
switches and inductor. The nominal input voltage
range is 2.5-5.0V. The output can be set to common
voltages by connecting appropriate combinations of 3
voltage selection pins to ground. If different voltage
levels are required, provision is also made to allow
external programming. The feedback control loop is
voltage-mode and the part uses a low-noise PWM
topology. Up to 6A of output current can be drawn
from this converter. The 5MHz operating frequency
enables the use of small-size output capacitors.
The power supply also has protection features such as:
Additional features include:
PIN
37
38
39
40
41
42
43
44
45
46
47
48
5. This pin is used for engineering test purposes and reserved for future use. Solder, but do not electrically connect this pin to
• Programmable over-current protection (to
• Thermal shutdown (to protect the converter
• Over-voltage protection that stops the PWM
• Under-voltage lockout circuit to disable the
the PCB.
protect the IC from excessive load current)
from getting too hot)
switching and turns on the lower N-MOSFET
at 120% of the programmed output voltage in
order to protect the load from an OV
condition.
converter output when the input voltage is less
than approximately 2.2V
NAME
AGND
ROCP
AVIN
POK
VS2
VS1
VS0
SS
Voltage select line 2 input. See Table 1.
Over-Current trip point adjust input. Used for adjusting the OCP trip point.
Voltage select line 1 input. See Table 1.
Analog voltage input for the controller circuits.
Analog ground for the controller circuits.
Voltage select line 0 input. See Table 1.
Power OK is an open drain transistor for power system state indication.
Soft-Start node. A capacitor is connected between this pin and AGND.
7
Output Voltage Programming
The EN5360 output voltage is programmed using one
of two methods. Common output voltages are
achieved by tying one or more of the three Voltage
Select pins (VS0, VS1 & VS2) to ground (see Table
1). If all three are left floating, the output voltage and
over voltage thresholds are determined by the voltages
presented at the XFB and XOV pins respectively.
These voltages should be set by way of resistor
dividers between V
going to XFB and XOV (See Figure 1).
FUNCTION
• Soft-start circuit, limiting the in-rush current
• Power good circuit indicating whether the
when the converter is powered up.
output voltage is within 90%-120% of the
programmed voltage.
OUT
to AGND with the midpoint
EN5360
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