Low Voltage Bias Stabilizer with Enable

• Maintains Stable Bias Current in N−Type Discrete Bipolar Junction and Field Effect Transistors
• Provides Stable Bias Using a Single Component Without Use of Emitter Ballast and Bypass Components
• Operates Over a Wide Range of Supply Voltages Down to 1.8 Vdc
• Reduces Bias Current Variation Due to Temperature and Unit−to−Unit Parametric Changes
• Consumes
0.5 mW at VCC = 2.75 V
• Active High Enable is CMOS Compatible

This device provides a reference voltage and acts as a DC feedback element around an external discrete, NPN BJT or N−Channel FET. It allows the external transistor to have its emitter/source directly grounded and still operate with a stable collector/drain DC current. It is primarily intended to stabilize the bias of discrete RF stages operating from a low voltage regulated supply, but can also be used to stabilize the bias current of any linear stage in order to eliminate emitter/source bypassing and achieve tighter bias regulation over temperature and unit variations. The “ENABLE” polarity nulls internal current, Enable current, and RF transistor current in “STANDBY.” This device is intended to replace a circuit of three to six discrete components.

The combination of low supply voltage, low quiescent current drain, and small package make the MDC5001T1 ideal for portable communications applications such as:
• Cellular Telephones
• Pagers
• PCN/PCS Portables
• GPS Receivers
• PCMCIA RF Modems
• Cordless Phones
• Broadband and Multiband Transceivers and Other Portable Wireless Products