A6300A
AiT Semiconductor Inc.
www.ait-ic.com
LOW DROPOUT VOLTAGE REGULATOR
300mA CMOS ULTRA LOW NOISE AND FAST RESPONSE
DEATILED INFORMATION
Like any low-dropout regulator, the external capacitors used with the A6300A must be carefully selected for
regulator stability and performance. Using a capacitor whose value is > 1μF on the A6300A input and the
amount of capacitance can be increased without limit. The input capacitor must be located a distance of not
more than 0.5 inch from the input pin of the IC and returned to a clean analog ground. Any good quality
ceramic or tantalum can be used for this capacitor. The capacitor with larger value and lower ESR (equivalent
series resistance) provides better PSRR and line-transient response. The output capacitor must meet both
requirements for minimum amount of capacitance and ESR in all LDOs application.
The A6300A is designed specifically to work with low ESR ceramic output capacitor in space-saving and
performance consideration. Using a ceramic capacitor whose value is at least 1μF with ESR is > 25mΩ on the
A6300A output ensur-es stability. The A6300A still works well with output capacitor of other types due to the
wide stable ESR range. Output capacitor of larger capacitance can reduce noise and improve load transient
response, stability, and PSRR. The output capacitor should be located not more than 0.5 inch from the VOUT
pin of the A6300A and returned to a clean analog ground.
Bypass Capacitor and Low Noise
Connecting a 22nF between the BP pin and GND pin significantly reduces noise on the regulator output, it is
critical that the capacitor connection between the BP pin and GND pin be direct and PCB traces should be as
short as possible. There is a relationship between the bypass capacitor value and the LDO regulator turn on
time. DC leakage on this pin can affect the LDO regulator output noise and voltage regulation performance.
Enable Function
The A6300A features an LDO regulator enable/ disable function. To assure the LDO regulator will switch on;
the CE turn on control level must be greater than 1.2 volts. The LDO regulator will go into the shutdown mode
when the voltage on the CE pin falls below 0.4 volts. For to protect the system, the A6300A have a quick
discharge function. If the enable function is not needed in a specific application, it may be tied to VDD to keep
the LDO regulator in a continuously on state.
Thermal Considerations
Thermal protection limits power dissipation in A6300A. When the operation junction temperature exceeds 165
℃, the OTP circuit starts the thermal shutdown function turn the pass element off. The pass element turns on
again after the junction temperature cools by 30℃. For continue operation, do not exceed absolute maximum
operation junction temperature 125℃. The power dissipation definition in device is:
PD = (VIN−VOUT) ×IOUT + VIN×IQ
The maximum power dissipation depends on the thermal resistance of IC package, PCB layout, the rate of
surroundings airflow and temperature difference between junctions to ambient. The maximum power
dissipation can be calculated by following formula：
PD (MAX) = (TJ (MAX) − TA) /θJA
REV1.4
-FEB 2010 RELEASED, DEC 2012 UPDATE –
- 8 -
AITSEMI [ AiT Semiconductor ]
