The MAX2251 low-voltage linear power amplifier (PA) is designed for TDMA/AMPS dual-mode phone applications. The device is packaged in an ultra-compact (2.06mm x 2.06mm) chip-scale package (CSP), and delivers over +30dBm of linear power in TDMA operation. An on-chip shutdown feature reduces operating current to 1µA (typ), eliminating the need for an external supply switch. The MAX2251 does not need an external reference voltage, and requires only a few external matching components and no bias circuitry. Another feature of this device is the use of external bias resistors, eliminating wasted "safety-margin" current. This feature also allows current throttleback at lower output power levels, thereby maintaining the highest possible efficiency at all power levels. Applications * 2-Way Pagers * Cellular-Band TDMA/AMPS Dual Mode™ Phones * Cordless Phones * PA Modules * Ultra-Compact 4 x 4 (2.06mm x 2.06mm) CSP * High Efficiency—41% at +30dBm POUT (TDMA) (typ) * On-Chip Power Detector * ICC < 1µA in Shutdown Mode * +2.8V to +4.5V True Single-Supply Operation * ±0.9dB Gain Variation from TA = -40°C to +85°C * Current Adjustable with PDM or DAC signal * No External Logic Interface Circuitry Required