LM6219-3.3N5 Datasheet, PDF (6/9 Pages) Cystech Electonics Corp. – 300mA High Speed LDO Regulator

CYStech Electronics Corp.
Spec. No. : C150N5
Issued Date : 2013.08.30
Revised Date : 2015.05.11
Page No. : 6/9
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 VOUT pin, is then driven by the subsequent output signal. The
output voltage at the VOUT pin is controlled and stabilized by a system of negative feedback. The current limit circuit
and short protect circuit operate in relation to the level of output current. Further, the IC's internal circuitry can be
shutdown via the CE pin's signal
●Low ESR Capacitors
With the LM6219-3.3N5, a stable output voltage is achievable even if used with low ESR capacitors as a phase
compensation circuit is built-in. In order to ensure the effectiveness of the phase compensation, we suggest that an
output capacitor (CL) is connected as close as possible to the output pin (VOUT) and the VSS pin. Please use an output
capacitor with a capacitance value of at least 1.0μF. Also, please connect an input capacitor (CIN) of 1.0μF between
the VIN pin and the VSS pin in order to ensure a stable power input.
Stable phase compensation may not be ensured if the capacitor runs out capacitance when depending on bias
and temperature. In case the capacitor depends on the bias and temperature, please make sure the capacitor can
ensure the actual capacitance.
●Current Limiter, Short-Circuit Protection
The LM6219-3.3N5 includes a combination of a fixed current limiter circuit & a foldback circuit, which aid the
operations of the current limiter and circuit protection. When the load current reaches the current limit level, the
fixed current limiter circuit operates and output voltage drops. As a result of this drop in output voltage, the
foldback circuit operates, output voltage drops further and output current decreases. When the output pin is shorted,
a current of about 50mA flows.
●CE Pin
The IC's internal circuitry can be shutdown via the signal from the CE pin with the LM6219-3.3N5. In shutdown
mode, output at the VOUT pin will be pulled down to the VSS level via R1 & R2. The operational logic of the IC's
CE pin is selectable (please refer to the selection guide). Although the CE pin is equal to an inverter input with CMOS
hysteresis, with either the pull-up or pull-down options, the CE pin input current will increase when the IC is in
operation. We suggest that you use this IC with either a VIN voltage or a VSS voltage input at the CE pin. If this IC is
used with the correct specifications for the CE pin, the operational logic is fixed and the IC will operate normally.
However, supply current may increase as a result of through current in the IC's internal circuitry.
LM6219-3.3N5
CYStek Product Specification