AP7335-10SNG-7 Diodes Inc, AP7335-10SNG-7 Datasheet - Page 11

• Manufacturer Part Number: AP7335-10SNG-7
• Description: Low Dropout (LDO) Regulators 300mA LDO REG 35uA 2 to 6 Vin
• Manufacturer: Diodes Inc

Specifications of AP7335-10SNG-7

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Application Note
Input Capacitor
A 1μF ceramic capacitor is recommended between IN and
GND pins to decouple input power supply glitch and noise.
The amount of the capacitance may be increased without
limit. This input capacitor must be located as close as
possible to the device to assure input stability and reduce
noise. For PCB layout, a wide copper trace is required for
both IN and GND pins. A lower ESR capacitor type allows
the use of less capacitance, while higher ESR type
requires more capacitance.
Output Capacitor
The output capacitor is required to stabilize and improve
the transient response of the LDO. The AP7335 is stable
with very small ceramic output capacitors. Using a ceramic
capacitor value that is at least 1μF with ESR > 15mΩ on
the output ensures stability. Higher capacitance values
help to improve line and load transient response. The
output capacitance may be increased to keep low
undershoot and overshoot. Output capacitor must be
placed as close as possible to OUT and GND pins.
Adjustable Operation
The AP7335 provides output voltage from 0.8V to 5.0V
through external resistor divider as shown below.
AP7335
Document number: DS32259 Rev. 2 - 2
V
IN
0.001
0.01
100
1 u F
0.1
10
1
Region of Stable C
0
E n a b le
Stable
R
50
Unstable Range
E N
IN
Unstable Range
A P 7335
100
Load Current (mA)
G N D
OUT
150
O U T
A D J
ESR vs. Load Current
V
C
IN
IN
=4.3V
=C
200
R 1
R 2
OUT
=1μF
250
V
O U T
1u F
300
www.diodes.com
300mA, Low Quiescent Current, Fast Transient
11 of 17
The output voltage is calculated by:
Where V
Rearranging the equation will give the following that is
used for adjusting the output to a particular voltage:
To maintain the stability of the internal reference voltage,
R
No Load Stability
Other than external resistor divider, no minimum load is
required to keep the device stable. The device will remain
stable and regulated in no load condition.
ON/OFF Input Operation
The AP7335 is turned on by setting the EN pin high, and is
turned off by pulling it low. If this feature is not used, the
EN pin should be tied to IN pin to keep the regulator
output on at all time. To ensure proper operation, the
signal source used to drive the EN pin must be able to
swing above and below the specified turn-on/off voltage
thresholds listed in the Electrical Characteristics section
under V
Current Limit Protection
When output current at OUT pin is higher than current limit
threshold, the current limit protection will be triggered and
clamp the output current to approximately 600mA to
prevent over-current and to protect the regulator from
damage due to overheating.
Short Circuit Protection
When OUT pin is short-circuit to GND, short circuit
protection will be triggered and clamp the output current to
approximately 140mA. This feature protects the regulator
from over-current and damage due to overheating.
Thermal Shutdown Protection
Thermal protection disables the output when the junction
temperature rises to approximately +145°C, allowing the
device to cool down. When the junction temperature
reduces to approximately +130°C the output circuitry is
enabled
thermal resistance,
thermal protection
This cycling limits the heat dissipation of the regulator,
protecting
2
need to be kept smaller than 80k Ω .
IL
REF
and V
again.
=0.8V (the internal reference voltage)
it from damage
Low Dropout Linear Regulator
IH
.
V
OUT
R
Depending
1
circuit
and
=
R
=
2
V
⎛
⎜
⎜
⎝
REF
V
V
ambient
may
OUT
REF
⎛
⎜
⎜
⎝
due
1
on
+
−
cycle
R
R
1
2
1
⎞
⎟
⎟
⎠
power
⎞
⎟
⎟
⎠
temperature,
AP7335
to
© Diodes Incorporated
September 2010
on
overheating.
dissipation,
and
the
off.