SMALLBLOCK Low Voltage Blas Stabilizer
• Maintains Stable Bias Current in Various 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
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. This device is intended to replace a circuit of three to six discrete components and is available in a SOT–143 package.
The combination of low supply voltage, low quiescent current drain, and small package make it ideal for portable communications applications such as:
• Cellular Telephones
• Pagers
• PCN/PCS Portables
• PCMCIA RF Modems
• Cordless Phones
• Broadband Transceivers and Other Portable Wireless Products