AN1431T, AN1431M Surface-mount Adjustable Output Shunt Regulator ■ Overview AN1431T Unit : mm The AN1431T and AN1431M are high accuracy stabilized power supplies in which the output voltage can be adjusted in the range from approx. 2.5 to 36V by using the external resistor under the operating temperature. Because of its fast rise characteristics, it can be replaced with Zener diode and has the wide application range. 4.0±0.2 13.5±0.5 5.1±0.2 5.0±0.2 ■ Features • High precision reference voltage : 2.5V±2% • High-temperature stability : 17ppm/˚C typ. • Output voltage externally adjustable : 2.5 to 36V • Fast rise • Low input impedance : 0.2Ω (typ.) • Low output noise voltage +0.2 0.45 – 0.1 2.54 2.3±0.2 2 3 1 JEDEC : TO-92 (SSIP003-P-0000) ■ Pin Name AN1431M 〈AN1431T〉 4.0±0.2 Pin name Cathode 2 Reference pin 3 Anode 13.5±0.5 1 5.1±0.2 Pin No. Unit : mm 5.0±0.2 〈AN1431M〉 Pin No. Pin name 1 Reference pin 2 Anode 3 Cathode +0.2 0.45 – 0.1 2.54 2.3±0.2 2 3 1 JEDEC : TO-92 (SSIP003-P-0000) ■ Block Diagram Current Source Output Tr 1 3 IK + Error Amp. – Voltage Reference 3 2 2 1 V1 VKA = VREF (1 + R2 = 2.5kΩ R1 R2 Pin number in Pin number in is for the AN1431T. is for the AN1431M. ) + IREF · R1 IREF VKA R1 R2 VREF ■ Absolute Maximum Ratings (Ta=25˚C) Symbol Rating Supply voltage Parameter VCC 37 Unit Supply current ICC mW mA V Power dissipation PD –100 to+150 650 * Reference input current IREF – 0.05 to+10 Operating ambient temperature Storage temperature AN1431T –20 to+85 Vopr AN1431M AN1431T ˚C –25 to+80 –55 to+150 Tstg AN1431M mA ˚C –55 to+125 * For the AN1431M, SM to the printed board (glass epoxy of 20 × 20 × 1.7mm with copper film of 1cm2) ■ Recommended Operating Range (Ta=25˚C) Parameter Symbol Range VKA VREF (2.5 to 36V) Operating supply voltage range ■ Electrical Characteristics (Ta=25˚C) Parameter Reference voltage Reference voltage temperature deviation Reference voltage fluctuation Reference input current Reference input current temperature deviation Symbol Condition VREF VREF (Jev) *1 *2 VKA=VREF, IK=10mA VKA=VREF, IK=10mA, Ta=0 to+70˚C min typ 2.45 2.50 max 2.55 Unit V 3 17 mV –1.2 –2.7 mV/V ∆VREF IK=10mA, DVKA=10V to VREF ∆VKA IK=10mA, DVKA=36 to 10V –1 –2 mV/V IREF IK=10mA, R1=10kΩ, R2= ∞ IK=10mA, R1=10kΩ, R2= ∞, Ta=0 to+70˚C 2 4 µA 0.4 1.2 µA IREF (Jev) * 2 Minimum cathode current Imin VKA=VREF 0.4 1.0 mA Off-state cathode current IOFF VKA=36V, VREF=0V VKA=VREF, IK=1 to 100mA, f< = 1kHz 0.1 1.0 µA 0.2 0.5 Ω Dynamic impedance |ZKA| *3 *1 VREF The temperature coefficient aVREF for the reference input voltage is equivalently given by the following expression. VREF (dev) = VREF (max) –VREF (min) VREF (max) |aVREF|= VREF (dev) * VREF at Ta=25˚C For example, assuming the following ; VREF (max) =2500mV (Ta=30˚C), VREF (min) =2497mV (Ta=0˚C), (VREF (dev) =3mV), VREF=2499mV (Ta=25˚C) ∆Ta=70˚C VREF (min) ∆Ta IREF VREF (dev) VREF* × 106 (ppm/˚C) ∆Ta IREF (dev) = IREF (max) – IREF (min) Then, the following expression is established. IREF (max) IREF (dev) 3mV |aVREF| = 2499mV × 106=17.1 (ppm/˚C) 70˚C *2 These values are design reference values, not guaranteed ones. *3 IREF (min) The dynamic impedance is defined by the following expression. |ZKA| = ∆Ta ∆VKA ∆IK The total dynamic impedance at ∆VREF, ∆VKA, IREF, and IREF (dev) is as follows. ∆V R1 |Z| = ∆I = |ZKA| 1 + R 2 ■ Power Dissipation PD – Ta 1000 Mounting onto Substrate : 20 × 20 × 1.7mm Glass Epoxy Substrate, Copper Foil 1cm2 or More Power Dissipation PD (mW) 900 800 700 600 500 400 300 200 100 0 0 20 40 60 80 100 120 140 160 Ambient Temperature Ta (˚C) ■ Application Circuits 1.Shunt Regulator 2.Constant Current Power Supply +V VO 3.Constant Current Source +V +V IO R1 VREF AN1431T/M AN1431T/M R2 AN1431T/M RS RS VO = 1+ R1 V R2 REF IO = 4.Current Boost VREF RS IO = 5.Adjustable Output Regulator Combined with 3-pin Regulator +V VO +V VO AN7805 R1 R1 VREF AN1431T/M CI AN1431T/M CO VREF R2 R2 VO = 1+ R1 V R2 REF VO = VREF 1+ R1 = VREF + 5V V R2 O (min) ■ Characteristics Curve VREF – Ta IREF – Ta 4 Reference Voltage VREF (mV) VK=VREF IK=10mA 2650 2600 2550 2500 2450 2400 2350 –50 –25 0 25 50 75 100 125 Ambient Temperature Ta (˚C) Reference Input Current IREF (µA) 2700 IK=10mA R1=10kΩ R2= ∞ 3 2 1 –40 –20 0 20 40 60 80 100 Ambient Temperature Ta (˚C) VREF RS IO