When it is configured for DDR termination applications, VTTREF buffers the DDR VTT reference voltage for the memory application. The VTTREF block consists of an on-chip 1/2 resistor divider and a low-pass filter (LPF). VTTREF tracks 1/2 of VDDQSNS typically within ±1%. It is typically capable of supporting a ±10 mA sink/source load current. VTTREF becomes active when VDDQSNS reaches 0.75V and VDD is above the UVLO threshold. When VTTREF is less than 0.675 V, VTTREF is disabled and subsequently discharges to GND through an internal MOSFET. VTT is also discharged following the discharge of VTTREF. VTTREF is independent of the EN pin state. To meet stability criteria, a ceramic capacitor of 0.1-µF minimum must be installed close to VTTREF (pin 4). Capacitor value at VTTREF (pin 4) must not exceed 2.2 µF.