XC6220 Datasheet, PDF (10/30 Pages) Torex Semiconductor – 1A LDO Voltage Regulator with “GreenOperation”

XC6220 Series
■OPERATIONAL EXPLANATION (Continued)
<CL High Speed Auto-Discharge Function>
The XC6220B/D series can quickly discharge the electric charge at the output capacitor (C_L), when a low signal to the CE
pin, which enables the whole IC circuit put into an OFF state, is inputted to the CE pin via the N-channel transistor located
between the VOUT pin and the VSS pin (cf. BLOCK DIAGRAM). The C_L auto-discharge resistance value is fixed to 460Ω
(VIN=6.0V, VOUT=5.0V at TYP.). The discharge time of the output capacitor (C_L) is set by the C_L auto-discharge resistance
(R_DCHG) and the output capacitor (C_L). By setting a time constant of the C_L auto-discharge resistance value [R_DCHG] and an
output capacitor value (C_L) as τ(τ=C x R_DCHG), the output voltage after discharge via the N channel transistor is calculated
by the following formulas.
V = V_OUT x e ^–t/τ, or ｔ=τln（ V_OUT(E) / V ）
where
V : Output voltage after discharge
V_OUT(E) : Output voltage
t: Discharge time
τ: C_L auto-discharge resistance R_DCHG×Output capacitor (C_L) value C)
For the XC6220A/C series, output voltage may rises when in the high stand-by mode. Please note that in that case, the
typical characteristics may worse. When the XC6220A/C series is used, please be noted the characteristics shown below.
XC6220A501xx
Output Voltage vs. Input Voltage
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
20
40
60
80
100
Ta (℃)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
1.0
2.0
3.0
4.0
5.0
6.0
VIN (V)
<Thermal Shutdown>
When the junction temperature of the built-in driver transistor reaches the temperature limit level (150℃ TYP.), the thermal
shutdown circuit operates and the driver transistor will be turned OFF. The IC resumes its operation when the thermal
shutdown function is released and the IC’s operation is automatically restored because the junction temperature drops to the
level of the thermal shutdown release voltage.
<Inrush Current Protection>
The XC6220 series includes an inrush current protection circuit.
The inrush current protection circuit suppresses inrush current charged to C_L when the IC starts up to 700 mA (MAX.) for
approximately 1 ms.
* Please note that the device can not provide the output current beyond 700 mA for a period of approximately 1 ms after the
CE pin goes high.
■NOTES ON USE
1. Please use this IC within the stated absolute maximum ratings. The IC is liable to malfunction should the ratings be
exceeded.
2. Where wiring impedance is high, operations may become unstable due to noise and/or phase lag depending on output current.
Please strengthen VIN and VSS wiring in particular.
3. Please wire the input capacitor (CIN) and the output capacitor (CL) as close to the IC as possible.
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