STC431 Programmable Voltage Reference Features • • • • • • • Programmable output voltage to 36 volts Sink current capability of 1.0mA to 100mA Low dynamic impedance 0.15Ω typical Temperature compensated for operation over full rated operating temperature Equivalent full-range temperature coefficient of 50ppm/°C (Typical) Low output Noise voltage Voltage reference tolerance : ±1.0% (Ta=25℃) Ordering Information Type NO. Marking STC431 Package Code STC431 TO-92 Outline Dimensions unit : mm Symbol 3.45±0.1 4.5±0.1 4.5±0.1 2.25±0.1 0.4±0.02 2.06±0.1 Functional block diagram 1.27 Typ. 2.54 Typ. 0.38 1.20±0.1 123 PIN Connections 1. Reference 2. Anode 3. Cathode 1 STC431 Absolute maximum ratings (Operating ambient temperature range applies unless other specified) Parameter Symbol Ratings Unit VKA 37 V Cathode current range(Continuous) IK -100 ~+150 mA Reference input current range(Continuous) Iref -0.05~+10 mA Power dissipation PD * 700 mW Operating temperature range Topr -40~+85 °C Storage temperature range Tstg -65~+150 °C Cathode to anode voltage Recommended operating conditions Parameter Symbol Cathode to Anode voltage Cathode current range(Continuous) Ratings Unit Min. Max. VKA Vref 36 V IK 1.0 100 mA Electrical Characteristics (Ambient temperature at 25°C, unless otherwise noted.) Parameter Symbol Reference input voltage (Fig. 1, Note 1) Deviation of reference input voltage Over temperature(Fig. 1, Note 1,2) Ratio of change in reference input Voltage to the change in cathode Voltage(Fig. 2) Vref Fig. 1 Fig. 2 Unit VKA=Vref, IK=10mA 2.47 2.495 2.52 V - 7.0 30 mV - 1.2 0.7 2.7 2.0 mV/V - 1.8 4.0 µA - 0.4 2.5 µA VKA=Vref - 0.35 1.0 mA IOFF VKA=36V, Vref=0V - 2.7 1000 nA ZKA VKA=Vref, f≤1.0KHz IKA=1.0mA-100mA - 0.14 0.5 Ω Iref Dynamic impedance(Fig. 1, Note 3) Max. IMIN ∆VKA Off-state cathode current(Fig. 3) Typ. ∆Iref ∆Vref Deviation of reference input voltage over temperature(Fig. 2) Minimum cathode current for Regulation(Fig. 1) Min. VKA=Vref , IK=10mA @Ta=TLOW to THIGH IK=10mA ∆VKA=10V-Vref ∆VKA=36V-10V IK=10mA R1=10KΩ, R2=∞ IK=10mA R1=10KΩ, R2=∞ ∆Vref Reference input current(Fig. 2) Condition Fig. 3 <Note 1> : TLOW=-40°C, THIGH=+85°C , <Note 2> : ∆Vref= Vref Max. - Vref Min. , <Note 3> : ZKA= ∆VKA/ ∆IK 2 STC431 Characteristic diagrams Fig. 4 IK vs. VKA Fig. 5 IMIN vs. VKA Fig. 6 ∆V ref vs. Ta Fig. 7 ∆Vref vs. VKA Fig. 8 Gv vs. frequency Fig. 9 Pulse reponse 3 STC 431 LINEAR INTEGRATED CIRCUIT APPLICATION CIRCUIT Vi Vi Vo IN Vi LM7805 COMMON OUT R1 VREF R1 R1 VREF VREF R2 R2 R2 STC 431 STC 431 STC 431 Vo=(1+R1/R2)*V REF Vo=(1+R1/R2)*V REF Fig 7 Shutdown Regulator Vo Vo Vo=(1+R1/R2)*V REF Fig 8 Output Control of a Three -Terminal Fixed Regulator Fig 9 Higher-current Shunt Regulator Vi Io Io Vi Vo Vo RCL Rs Rs STC 431 IO=VREF/RS RS=VREF/RCL STC 431 Fig 1 0 Constant-current Sink Fig 11 Current Limiting or Current Source TEST CIRCUIT VKA INPUT INPUT VKA IKA IKA INPUT VKA IKA(OFF) R1 IREF STC 431 VREF STC 431 R2 STC 431 VREF VKA=VREF*(1+R1/R2)+IREF*R1 Fig 12 Test Circuit For VKA=VREF Fig 1 3 Test Circuit for VKA >= VREF Fig 14Test Circuit For IKA(OFF) 4.