2.5V LOW POWER PRECISION REFERENCE SOURCE ZRT025 ISSUE 1 - OCTOBER 1995 DEVICE DESCRIPTION FEATURES The ZRT025 is a monolithic integrated circuit providing a precise stable reference voltage of 2.5V at 500µA. • • • • • The circuit features a knee current of 150µA and operation over a wide range of temperatures and currents. • The ZRT025 is available in a 3-pin metal can package for through hole applications as well as SOT223 and SO8 packages for surface mount applications. Each package option offers a trim facility whereby the output voltage can be adjusted as shown in F i g . 1. Thi s f a ci l i t y i s u sed w he n compensating for system errors or setting the reference output to a particular value. When the trim facility is not used, the pin should be left open circuit. • • • • SCHEMATIC DIAGRAM R VCC R=VCC-VR IR Gnd VR RT=100k (Optional trim facility) Gnd This circuit will allow the reference to be trimmed over a wide range. The device is specified over a 65% trim range. 4-279 Trimmable output Excellent temperature stability Low output noise figure Available in two temperature ranges 1 and 2% initial voltage tolerance versions available No external stabilising capacitor required in most cases Low slope resistance No derating required at low temperatures TO18 package SOT223 and SO8 small outline packages ZRT025 ABSOLUTE MAXIMUM RATING Reverse Current Operating Temperature A grade C grade Storage Temperature TO18 SO8, SOT223 Power Dissipation (Tamb=25°C) TO18 300mW SO8 625mW SOT223 2W ø Above 72°C this figure should be linearly derated to 25mA at 125°C 75mA ø -55°C to 125°C 0°C to 70°C -55 °C to 175 °C -55 °C to 125 °C TEMPERATURE DEPENDENT ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER INITIAL GRADE A VOLTAGE -55°C TO 125°C TOLERANCE TYP MAX % GRADE C 0°C TO 70°C TYP MAX UNITS DVR Output voltage change over relevant temperature range (See note (a)) 1&2 6.8 22.5 2.7 8.8 mV TCVR Output voltage temperature coefficient (See note (b)) 1&2 15.0 50.0 15.0 50.0 ppm/°C ELECTRICAL CHARACTERISTICS ( at Tamb=25°C and Trim pin o/c unless otherwise stated) SYMBOL PARAMETER VR Output voltage 1% tolerance (A1,C1) 2% tolerance (C2) DVTRIM MIN. TYP. 2.475 2.500 2.450 2.500 MAX. UNITS 2.525 V 2.550 Output voltage adjustment range 65 % TCDVTRIM Change in TCVR with output adjustment 2.5 ppm/°C/% COMMENTS IR=500µA RT=100kΩ IR Operating current range ton toff Turn-on time Turn-off time 10 0.3 µs RL=1kΩ enp-p Output voltage noise (over the range 0.1 to 10Hz) 50 µV Peak to peak measurement RS Slope resistance 0.85 Ω IR= 0.5mA to 5mA See note (c) 0.15 4-280 75 2.0 mA ZRT025 TYPICAL CHARACTERISTICS NOTES (c) Slope resistance (RS) (a) Output change with temperature The slope resistance is defined as : The absolute maximum difference between the maximum output voltage and the minimum output voltage over the specified temperature range RS = ∆I = 5 - 0.5 = 4.5mA (typically) DVR = Vmax - Vmin (d) Line regulation The ratio of change in output voltage to the change in input voltage producing it. (b) Output temperature coefficient (TCVR) The ratio of the output change with temperature to the specified temperature range expressed in ppm/°C TcVR = changein VR specifiedcurrentrange RS x 100 %⁄V VR x Rsource ∆VR x 106 ppm ⁄ °C VR x ∆T ∆T= Full temperature range 4-281 ZRT025 CONNECTION DIAGRAMS SOT223 Package Suffix – G TO18 Top View Pin 4 floating or connected to pin 2 Package Suffix – None Bottom View – Case is internally connected to pin 3 SO8 Package Suffix – N8 Top View ORDERING INFORMATION Part No Tol% Operating Temp.(°C) Package Partmark ZRT025C2 2 0 to 70 TO18 ZRT025C2 ZRT025C1 1 0 to 70 TO18 ZRT025C1 ZRT025A1 1 -55 to 125 TO18 ZRT025A1 ZRT025GC2 2 0 to 70 SOT223 ZRT025C2 ZRT025GC1 1 0 to 70 SOT223 ZRT025C1 ZRT025GA1 1 -55 to 125 SOT223 ZRT025A1 ZRT025N8C2 2 0 to 70 SO8 ZRT025C2 ZRT025N8C1 1 0 to 70 SO8 ZRT025C1 ZRT025N8A1 1 -55 to 125 SO8 ZRT025A1 4-282