EV0007 Datasheet, PDF (2/4 Pages) Monolithic Power Systems – 2A MP1580 Step Down Switch Mode Converter

Monolithic Power Systems
Figure 2: EV0007 Schematic
EV0007
2A MP1580 Step Down
Switch Mode Converter
EVALUATION BOARD
External
Power
Supply
-+
Available Output Voltages (VOUT)
L1
CN2
1.22 V 1.5 V 1.8 V 2.5 V 3.3 V 5 V VOUT
1
2
D1
C4
J1
J2
J3
J4
J5
J6
GND ³
4
CB
CN1
VIN=4.75V to 25V
1
2
GND
3 ^Sync
4 _EN
C1
1
BS
2
IN
3 _SW
4
GND
8
SYNC
7
EN
6
COMP
FB ⁵
U1
MP1580HS
RC
CCA
CC
R2A
R2B
R2C
R2D
R2E
External
Load
R1
Board Operation
This board is laid out to accommodate most commonly used Inductors and Output Capacitors and to
be programmed for most standard Output Voltages.
1) Attach positive end of load to pin 1 = 2 and negative end of load to pin 3 = 4 of connector CN2.
2) For the required output voltage (VOUT = 1.22, 1.5, 1.8, 2.5, 3.3 or 5V) solder blob the appropriate
J1 thru J6 jumper respectively.
3) Attach input voltage (VIN) and input ground (GND) to Pin 1 and 2 of connector CN1 respectively.
Note VIN must be 4.75V < VIN < 25V.
4) Pin 3 of CN1 is used to synchronize the internal oscillator frequency of the MP1580 to an external
source. The synchronization rate can be vary from 380KHZ (normal operation) to 600KHz. There
is an internal 11KΩ pull down resistor to GND therefore leave this pin unconnected if unused.
5) Applying a voltage greater than 2.495V to pin 4 of CN1 enables the MP1580. Leave the input
unconnected if unused. An Under Voltage Lockout (UVLO) function can be implemented by the
addition of a resistor divider from VIN to GND. For complete low current shutdown its needs
to be less than 0.7V.
EV0007 Rev 1.5_08/14/02
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