Datasheet

© 2011 Microchip Technology Inc. DS22049F-page 11
MCP1703
3.0 PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1: MCP1703 PIN FUNCTION TABLE
3.1 Ground Terminal (GND)
Regulator ground. Tie GND to the negative side of the
output and the negative side of the input capacitor.
Only the LDO bias current (2.0 µA typical) flows out of
this pin; there is no high current. The LDO output
regulation is referenced to this pin. Minimize voltage
drops between this pin and the negative side of the
load.
3.2 Regulated Output Voltage (V
OUT
)
Connect V
OUT
to the positive side of the load and the
positive terminal of the output capacitor. The positive
side of the output capacitor should be physically
located as close to the LDO V
OUT
pin as is practical.
The current flowing out of this pin is equal to the DC
load current.
3.3 Unregulated Input Voltage (V
IN
)
Connect V
IN
to the input unregulated source voltage.
Like all low dropout linear regulators, low source
impedance is necessary for the stable operation of the
LDO. The amount of capacitance required to ensure
low source impedance will depend on the proximity of
the input source capacitors or battery type. For most
applications, 1 µF of capacitance will ensure stable
operation of the LDO circuit. For applications that have
load currents below 100 mA, the input capacitance
requirement can be lowered. The type of capacitor
used can be ceramic, tantalum, or aluminum
electrolytic. The low ESR characteristics of the ceramic
will yield better noise and PSRR performance at
high-frequency.
3.4 Exposed Thermal Pad (EP)
There is an internal electrical connection between the
Exposed Thermal Pad (EP) and the V
SS
pin; they must
be connected to the same potential on the Printed
Circuit Board (PCB).
Pin No.
2x3 DFN-8
Pin No.
SOT-223-3
Pin No.
SOT-23A
Pin No.
SOT-89-3
Name Function
4 2,Tab 1 1 GND Ground Terminal
1323V
OUT
Regulated Voltage Output
8132,TabV
IN
Unregulated Supply Voltage
2, 3, 5, 6, 7 — — — NC No Connection
9 — — — EP Exposed Thermal Pad (EP); must be
connected to VSS