WSL431 Adjustable Precision Shunt Regulator Features • • • • • • • • Precise Reference Voltage to 2.505V Guaranteed 0.5%, 1% and 2% Reference Voltage Tolerance Sink Current Capability, 1mA to 100mA Quick Turn-on Adjustable Output Voltage, Vo = Vref to 20V Low Operational Cathode Current, 150μA Typical 0.1Ω Typical Output Impedance SOT-89 , TO-92 and SOT-23 Packages This device has a typical output impedance of o.1Ω. Active output circuitry provides a very sharp turn-on characteristic, making the WSL431 excellent replacements for zener diodes in many applications, including on-board Regulation and adjustable power supplies. Applications • Linear Regulators • Adjustable Power Supply • Switching Power Supply REF ANODE CATHODE General Description SOT-89 (Top View) The WSL431 is a 3 terminal adjustable voltage reference with specified thermal stability over applicable commercial temperature ranges. Output voltage may be set to any value between Vref (2.505V) and 20V with two external resistors (see Figure 2). When used with a photocoupler, the WSL431 is an ideal voltage reference in isolated feedback circuits for 2.505V to 12V switching-mode power supplies. TO-92 SOT-23 (Top View) Winson reserves the right to make changes to improve reliability or manufacturability. ©Winson, Jan. 2000 (Rev. C) WSL431 Ordering Information WSL431-XP□N□ Elec. Grad 2: 0.5% Reference Voltage Tolerance 3: 1% Reference Voltage Tolerance 4: 2% Reference Voltage Tolerance Elec. Grade Package Code Package Code A: TO-92 C: SOT-23 N: SOT-89 N: No-Lead Product Symbol REF ANODE CATHODE Functional Diagram Winson reserves the right to make changes to improve reliability or manufacturability. ©Winson, Jan. 2000 (Rev. C) WSL431 Absolute Maximum Ratings Symbol VKA IK Iref TA TJ TSTG TSO Parameter Cathode voltage Continuous cathode current range Reference current range Ambient temperature range Junction temperature range Storage Temperature Range Lead temperature range, Ts (Soldering, 10sec) Electrical Characteristics Symbol Rating 26 150 3 0 to 85 0 to 125 -65 to 150 260 TA = 25˚C (unless otherwise noted) Parameter Test Conditions WSL431 Min. Vref VKA=Vref, IK=10mA. ΔVref/T Iref Reference Voltage Drift over Temp. range Voltage Ration (open loop gain) Reference Current ΔIref/T Reference Current Drift IK(min) IK(off) Min. Cathode Current Off-state Cathode Current Dynamic Impedance ΔVref/ΔVKA zKA Notes: WSL431B WSL431C WSL431D TA=0 to 85°C*1 , I k =10mA. 2.4925 2.480 2.455 IK=10 mA, VKA=Vref to 20V*2 -4 IK=10mA, R1=10KΩ, R2=open*2 IK=10 mA, R1=10KΩ, R2=open, TA=0 to 85°C*2 VKA=Vref*1 VKA=20V, Vref=0V*3 VKA=Vref, IK=1 mA to 100mA, f=1k Hz*1 -0.4 : use Figure 1 *2: use Figure 2 *3: use Figure 3 *1 Winson reserves the right to make changes to improve reliability or manufacturability. ©Winson, Jan. 2000 (Rev. C) Unit V mA mA ˚C ˚C ˚C ˚C Typ. Unit Max. 2.505 2.5175 2.505 2.530 2.505 2.555 4 20 - 1.6 mV 0.4 3.5 mV/ V µA 0.4 1.2 µA 0.15 0.1 -0.1 0.4 1 mA µA Ω WSL431 Test figures Figure 1. Test Circuit for VKA=VREF VO=VKA =VREF Figure 2. Test Circuit for VKA<VREF, VO=VKA=VREF×(1+R1/R2)+IREF×R1 Figure 3. Test Circuit for Ik(off) Winson reserves the right to make changes to improve reliability or manufacturability. ©Winson, Jan. 2000 (Rev. C) WSL431 TYPICAL CHARACTERISTICS Vref. vs Free-Air Temperature Iref vs Free-Air Temperature 0.6 2.525 2.52 0.5 2.515 0.4 2.518 V 2.499 V 2.480 V 2.5 2.495 Iref. (uA) Vref. (V) 2.51 2.505 0.3 2.49 0.2 2.485 2.48 0.1 2.475 0 20 30 40 50 60 70 80 90 20 100 110 120 30 40 50 60 70 80 C Ik(off) vs Free-Air Temperature 110 120 Ratio of Delta Vref to Delta Vk vs Temperature 1.4 0 10 1.2 20 30 40 50 60 70 -0.5 dVref/dVk (mv/v) 1 0.8 0.6 0.4 0.2 -1 -1.5 -2 -2.5 -3 0 0 20 40 60 80 100 120 140 -3.5 o o C C Cathode Current vs Cathode Voltage 800 700 IKA - uA Ik(off) - (uA) 100 C o -0.2 90 o 600 VKA=Vref 500 TA=25°C 400 Imin 300 200 100 0 -100 -200 -1 -0.5 0 0.5 1 1.5 2 2.5 3 VKA - V Winson reserves the right to make changes to improve reliability or manufacturability. ©Winson, Jan. 2000 (Rev. C) 80 90 100 110 120 WSL431 Application schematic 5-Volt Precision Regulator *Rb should provide cathode current large than 0.4mA to maintain WSL431work properly. Figure 4. Figure 5. Figure 6. Winson reserves the right to make changes to improve reliability or manufacturability. ©Winson, Jan. 2000 (Rev. C) WSL431 Figure 7. Figure 8. Figure 9. Winson reserves the right to make changes to improve reliability or manufacturability. ©Winson, Jan. 2000 (Rev. C)