Voltage Regulators AN1432MS Variable output, low voltage operation shunt regulator IC The AN1432MS is a low voltage operation and positive voltage variable output type shunt regulator IC. Since the output voltage is adjustable from approximately 1.26 V to 15 V, it is suitable for a power supply of small-sized 3 V-system portable equipment. Also, it contributes to the miniaturization of set equipment by the adoption of the small type surface mounting package. 0.40 1.45 Unit: mm 0.65 ± 0.15 ■ Overview + 0.10 – 0.05 0.16 +– 0.10 0.06 1.90 ± 0.20 2.90 –+ 0.20 0.05 ■ Features 0.40 ± 0.20 5° 2 0.95 0.65 ± 0.15 1 0.95 2.80 +– 0.20 0.30 1.50 +– 0.25 0.05 3 + 0.20 0 to 0.1 1.10 – 0.10 0.30 1.10 +– 0.10 10° • High precision reference voltage: 1.26 V (allowance: ±2%) • Low voltage operation: 1.26 V to 15 V • Small type surface mounting package MINI-3D ■ Applications • Portable telephone, PHS, office automation equipment, and other small-sized portable equipment 2 K ■ Block Diagram Constant current source 1 Error amplifier Output transistor 3 Reference voltage A Ref. 1 AN1432MS Voltage Regulators ■ Pin Descriptions Pin No. Symbol Description 1 Reference The reference voltage (1.26 V typical) pin. Although the impedance is high under the normal using conditions, be careful that the impedance drops and current flows into the IC inside if a current or voltage is forced to apply from the outside. 2 Cathode The pin for the combined use of the power source current supply of IC and the constant voltage output as the shunt regulator. An excessive current supplied to this pin is bypassed to the anode pin through the output transistor. 3 Anode The constant voltage reference pin of the shunt regulator and flows out the current from the cathode and reference. Usually grounded. ■ Absolute Maximum Ratings Parameter Symbol Rating Unit VK 15 V VREF 7 V IK 20 mA Reference current IREF 50 µA Cathode anode reverse current −IKA −10 mA Cathode reference reverse current −IKR −10 mA PD 104 mW Topr −30 to +85 °C Tstg −55 to +150 °C Supply voltage Reference voltage Supply current Power dissipation *2 Operating ambient temperature Storage temperature *1 *1 Note) 1. Do not apply external currents or voltages to any pins not specifically mentioned. For circuit currents, '+' denotes current flowing into the IC, and '−' denotes current flowing out of the IC. 2. *1: Except for the operating ambient temperature and storage temperature, all ratings are for Ta = 25°C. *2: The value at Ta = 85°C. ■ Recommended Operating Range Parameter Supply voltage Symbol Range Unit VCC VREF to 15 V ■ Electrical Characteristics at Ta = 25°C Parameter 2 Symbol Conditions Min Typ Max Unit 1.235 1.26 1.285 V Reference voltage VREF VKA = VREF , IK = 10 mA Reference voltage fluctuation 1 ∆VREF /∆VKA VREF≤ VKA ≤ 5 V, IK = 10 mA 1.9 3.5 mV/V Reference voltage fluctuation 2 ∆VREF /∆VKA 5 V ≤ VKA ≤ 15 V, IK = 10 mA 1.0 2.0 mV/V Reference input current IREF RI = 10 kΩ, IK = 10 mA 2.5 4.4 µA Minimum cathode current IK min VKA = VREF 290 350 µA Off time cathode current IK OFF VKA = 15 V, VREF = 0 V 1.0 µA Dynamic impedance ZKA VKA = VREF , f ≤ 1 kHz, IK = 1 mA to 10 mA 0.1 0.5 Ω Voltage Regulators AN1432MS ■ Electrical Characteristics at Ta = 25°C (continued) • Design reference data Note) The characteristics listed below are theoretical values based on the IC design and are not guaranteed. Parameter Symbol Conditions Reference voltage change with temperature ∆VREF /∆Ta VKA = VREF , IKA = 10 mA 0 °C ≤ Ta ≤ +70 °C Reference input current change with temperature ∆IREF /∆Ta R1 =10 kΩ, IK = 10 mA 0 °C ≤ Ta ≤ +70 °C Reference value Unit 3 mV 0.4 µA ■ Application Notes • PD Ta curves of mini-type 3-pin package PD T a 200 Power dissipation PD (mW) 175 Independent IC Rth(j−a) = 625°C/W PD = 200 mW (25°C) 150 125 104 100 75 50 25 0 0 25 50 75 85 100 125 150 Ambient temperature Ta (°C) ■ Application Circuit Example This circuit amplifies the error voltage of the secondary side output voltage in the insulation type switching power supply, then transfer it to the primary side via a photocoupler. Replaceable with the conventional product (AN1431M/AN1431T). (Primary side) (Secondary side) VOUT AN1432 Primary side to control IC 3