XC6217_2 Datasheet, PDF (12/33 Pages) Torex Semiconductor – High Speed "Green Operation" LDO Voltage Regulators

XC6217 Series
■OPERATIONAL EXPLANATION
<Output Voltage Control>
The voltage divided by resistors R1 & R2 is compared with the internal reference voltage by the error amplifier. The
P-channel MOSFET, which is connected to the V_OUT pin, is then driven by the subsequent output signal. The output voltage
at the V_OUT pin is controlled & stabilized by a system of negative feedback. The current limit circuit and short protect circuit
operate in relation to the level of output current. The GO function monitors the output current and switches a supply current
to two values according to the level of output current. Further, the IC's internal circuitry can be shutdown via the CE pin's
signal.
<Green Operation>
XC6217A and B series can be set as a fixed high-speed mode or a green operation (GO) mode via a signal to the green
operation (GO) pin. Under the condition that the GO pin becomes low level, the IC operates in the GO mode and the IC
operates in the fixed high-speed mode when the GO pin is at high level. The GO mode enables the IC to switch
automatically the supply current to the high speed (HS) mode or the power save (PS) mode according to the level of output
current. While having both high-speed operation and low supply current state, the series can acquire high efficiency. At the
HS/PS automatic switching mode (GO mode), the switching point of the HS mode and the PS mode is being fixed inside the
IC. When the output current becomes I_GOR 0.5mA (MIN.) or below, the mode changes automatically to the PS mode after the
delay time of hundreds μsec(s), and it can reduce supply current in light load. Also when the output current becomes I_GO
8mA (MAX.) or more, the mode changes automatically to the HS mode and the IC becomes high speed operation.
When the XC6217 is used in the GO mode, stable operation range is over 8.0mA is HS mode and below 0.5mA in PS mode.
<Low ESR capacitor>
With the XC6217 series, a stable output voltage is achievable even if used with low ESR capacitors, as a phase
compensation circuit is built-in. Values required for the phase compensation are as the chart below. In order to ensure the
stable phase compensation while avoiding run-out of values, please use the capacitor which does not depend on bias or
temperature too much. For a stable power input, please connect an input capacitor (C_IN) of 1.0μF between the V_IN pin and
the V_SS pin.
・Excluding USPN-4
OUTPUT VOLTAGE (V)
0.8 ~ 1.15
1.2 ~ 1.35
1.4 ~ 4.0
OUTPUT CAPACITOR VALUE
More than C_L=4.7μF
More than C_L=2.2μF
More than C_L=1.0μF
・USPN-4
OUTPUT VOLTAGE (V)
1.6 ~ 4.0
OUTPUT CAPACITOR VALUE
More than C_L=2.2μF
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