AiT Semiconductor Inc.
A6303C
www.ait-ic.com
CMOS LOW DROPOUT REGULATOR (LDO)
300mA ULTRA-LOW NOISE, ULTRA-FAST RESPONSE
APPLICATIONS INFORMATION
Like any low-dropout regulator, the external capacitors used with the A6303C must be carefully selected for
regulator stability and performance. Using a capacitor whose value is > 1μF on the A6303C 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 A6303C 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
A6303C output ensures stability. The A6303C 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 A6303C and returned to a clean analog ground.
Enable Function
The A6303C features an LDO regulator enable/ disable function. To assure the LDO regulator will switch on;
the EN turn on control level must be greater than 1.2 volts.
The LDO regulator will go into the shutdown shutdown mode when the voltage on the EN pin falls below 0.4
volts. For to protect the system, the A6303C have a quick discharge function. If the enable function is not
needed in a specific application, it may be tied to VIN to keep the LDO regulator in a continuously on state.
Thermal Considerations
Thermal protection limits power dissipation in A6303C. When the operation junction temperature exceeds
170°C, 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°C. For continue operation, do not exceed absolute
maximum operation junction temperature 125°C. The power dissipation definition in device is:
PD(MAX) = ( TJ(MAX) − TA ) /θJA
Where TJ(MAX) is the maximum operation junction temperature 125°C, TA is the ambient temperature and the
θJA is the junction to ambient thermal resistance. For recommended operating conditions specification of
A6303C, where TJ(MAX) is the maximum junction temperature of the die (125°C) and TA is the maximum
REV1.0
- AUG 2018 RELEASED -
- 8 -
AITSEMI [ AiT Semiconductor ]
