The REG103 is a family of low-noise, low-dropout, linearregulators with low ground pin current. Its new DMOStopology provides significant improvement over previousdesigns, including low-dropout voltage (only 115mV typ atfull load), and better transient performance. In addition, nooutput capacitor is required for stability, unlike conventionallow-dropout regulators that are difficult to compensate andrequire expensive low ESR capacitors greater than 1µF.
Typical ground pin current is only 1mA (at IOUT = 500mA)and drops to 0.5µA in not enabled mode. Unlike regulatorswith PNP pass devices, quiescent current remains relativelyconstant over load variations and under dropout conditions.
The REG103 has very low output noise (typically 33µVrmsfor VOUT = 3.3V with CNR = 0.01µF), making it ideal for usein portable communications equipment. On-chip trimmingresults in high output voltage accuracy. Accuracy is maintainedover temperature, line, and load variations. Keyparameters are tested over the specified temperature range(–40°C to +85°C).
The SO-8 version of the REG103 has an ERROR pin thatprovides a power good flag, indicating the regulator is inregulation. The REG103 is well protected—internal circuitryprovides a current limit that protects the load fromdamage. Thermal protection circuitry keeps the chip frombeing damaged by excessive temperature. In addition to theSO-8 package, the REG103 is also available in the DDPAKand the SOT223-5.
NEW DMOS TOPOLOGY: Ultra Low Dropout Voltage: 115mV Typ at 500mA and 3.3V Output Output Capacitor NOT Required for Stability
FAST TRANSIENT RESPONSE
VERY LOW NOISE: 33µVrms
HIGH ACCURACY: ±2% max
HIGH EFFICIENCY: IGND = 1mA at IOUT = 500mA Not Enabled: IGND = 0.5µA
2.5V, 2.7V, 3.0V, 3.3V, 5.0V, AND ADJUSTABLE OUTPUT VERSIONS
FOLDBACK CURRENT LIMIT
OUTPUT VOLTAGE ERROR INDICATOR(1)
SMALL SURFACE-MOUNT PACKAGES: SOT223-5, DDPAK-5, SO-8