LX432

LX432 L OW V OLTAGE A DJUSTABLE P RECISION S HUNT R EGULATORS T HE I NFINITE P OWER OF I N N O VAT I O N P RODUCTION D ATA S HEET DESCRIPTION The LX432 series are low-voltage precision adjustable shunt regulators with a reference voltage of 1.24V. The output voltage may be set to any value between 1.24V and 20V by two external resistors. These devices offer low output impedance for improved load regulation — t ypical output impedance is 250mΩ. The LX432 series operates with an operating current as low as 80µA, making these devices suitable for portable and micropower applications. Low voltage operation enables the LX432 to be used in the feedback loop of isolated low voltage power supplies. The minimum output voltage is determined by the LX432 output voltage plus the forward voltage drop of the opto-coupler LED (typically 1.24 + 1.4 = 2.64V minimum). See Figure 10. The LX432 is offered in 3 and 5-pin SOT-23 or TO-92 packages, and is a dropin replacement for the TLV431 and SC431L devices. s s s s K E Y F E AT U R E S Low Voltage Operation: 1.24V Reference Initial Voltage Reference Accuracy 1% Adjustable Output Voltage From VREF To 20V Typical Output Dynamic Impedance Less Than 250mΩ s Sink Current Capability 80µA To 20mA s Direct Alternative To TLV431 A P P L I C AT I O N S s s s s Low Voltage Adjustable Power Supplies Instrumentation Computers Portable Equipment IMPORTANT: For the most current data, consult LinFinity's web site: http://www.linfinity.com. PRODUCT HIGHLIGHT T Y P I C A L P R O G R A M M A B L E V O LTA G E REFERENCE CIRCUIT VIN Cathode VKA R1 Reference LX432 Anode R2 GND PA C K A G E O R D E R I N F O R M AT I O N TA (°C) 0 to 70 -40 to 85 SC Plastic SOT-23 3-pin LX432CSC LX432ISC SE Plastic SOT-23 5-pin LX432CSE LX432ISE LP Plastic TO-92 3-pin LX432CLP LX432ILP Note: All surface-mount packages are available in Tape & Reel. Append the letter "T" to part number. (i.e. LX432CSET) TO-92 (LP) package also available in ammo-pack. Copyright © 1999 Rev. 1.0 9/99 LINFINITY MICROELECTRONICS INC. 11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841, 714-898-8121, FAX: 714-893-2570 1 PRODUCT DATABOOK 1996/1997 LX432 L OW V OLTAGE A DJUSTABLE P RECISION S HUNT R EGULATORS P RODUCTION D ATA S HEET A B S O L U T E M A X I M U M R AT I N G S (Note 1) PACKAGE PIN OUTS Cathode to Anode Voltage (VKA) ................................................................. -0.3V to +20V Reference Input Current (IREF) .................................................................... -50µA to 10µA Continuous Cathode Current (IK) ............................................................. -25mA to 25mA Operating Junction Temperature Plastic (SC, SE & LP Packages) ............................................................................. 150°C Storage Temperature Range ...................................................................... -65°C to 150°C Lead Temperature ..................................................................................................... 300°C Note 1. Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of the specified terminal. Pin numbers refer to DIL packages only. 2 CATHODE ANODE 3 1 REF SC PACKAGE — 3-Pin (Top View) T H E R M A L D ATA SC PACKAGE: Thermal Resistance - Junction to Ambient, θJA SE PACKAGE: Thermal Resistance - Junction to Ambient, θJA LP PACKAGE: Thermal Resistance-Junction to Ambient, θJA 156°C/W (PC-Mounted) (Non-PC Mounted) 220°C/W 410°C/W (PC-Mounted) (Non-PC Mounted) 220°C/W 410°C/W N.C. N.C. CATHODE 1 2 3 5 ANODE 4 REF SE PACKAGE — 5-Pin (Top View) 3. CATHODE 2. ANODE 1. REF Junction Temperature Calculation: TJ = TA + (PD x θJA). The θJA numbers are guidelines for the thermal performance of the device/pc-board system. All of the above assume no ambient airflow BLOCK DIAGRAM LP PACKAGE (Top View) Cathode (K) Ref (R) VREF Anode (A) 2 Copyright © 1999 Rev. 1.0 9/99 PRODUCT DATABOOK 1996/1997 LX432 L OW V OLTAGE A DJUSTABLE P RECISION S HUNT R EGULATORS P RODUCTION D ATA S HEET ELECTRICAL CHARACTERISTICS (Unless otherwise specified, these specifications apply over the operating ambient temperatures for LX432C with 0°C ≤ TA ≤ 70°C, and the LX432I with -40°C ≤ TA ≤ 85°C.) Parameter Reference Voltage Reference Voltage Drift (Note 2) Ratio Of VREF Change In Cathode Voltage Change (Note 3) Reference Terminal Current Reference Current Drift (Note 2) Minimum Cathode Current For Regulation Dynamic Impedance Off-state Cathode Current ∆VREF ∆VKA Symbol VREF ∆VREF ∆VREF ∆VKA IREF ∆IREF IK (MIN) ZKA IOFF Test Conditions IK = 10mA, VKA = VREF, TA = 25°C IK = 10mA, VKA = VREF, 0°C ≤ TA ≤ 70°C IK = 10mA, VKA = VREF, -40°C ≤ TA ≤ 85°C IK = 10mA, VKA = VREF to 16V, TA = 25°C IK = 10mA, VKA = VREF, TA = 25°C, R1=10kΩ, R2 = Open IK = 10mA, VKA = VREF, 0°C ≤ TA ≤ 70°C IK = 10mA, VKA = VREF, -40°C ≤ TA ≤ 85°C VKA = VREF, TA = 25°C IK = 0.1mA to 15mA, VKA = VREF, TA = 25°C VKA = 16V, TA = 25°C Min. 1.228 LX432 Typ. Max. 1.24 3 4 -1 0.1 0.05 0.1 55 0.2 0.004 1.252 12 20 -2.7 0.5 0.3 0.4 80 0.4 Units V mV mV mV/V µA µA µA µA Ω µA Note 2. These parameters are guaranteed by design. Note 3. Ratio of change in reference input voltage to the change in cathode voltage. Copyright © 1999 Rev. 1.0 9/99 3 PRODUCT DATABOOK 1996/1997 LX432 L OW V OLTAGE A DJUSTABLE P RECISION S HUNT R EGULATORS P RODUCTION D ATA S HEET GRAPH / CURVE INDEX FIGURE INDEX Characteristic Curves FIGURE # 1. 2. 3. 4. 5. 6. 7. 8. Reference Voltage vs. Junction Temperature Reference Current vs. Junction Temperature Cathode Current vs. Cathode Voltage ∆VREF / ∆VKA vs. Junction Temperature Dynamic Impedance vs. Junction Temperature Minimum Cathode Current For Regulation vs. Junction Temperature Off-State Current vs. Junction Temperature Equivalent Input Noise Voltage vs. Frequency FIGURE # FIGURE # 9. Parameter Measurement Information Test Circuit For VKA = VREF 10. Test Circuit For VKA > VREF 11. Test Circuit For IOFF Typical Applications 12. Flyback With Isolation Using LX431 Or LX431A As Voltage Reference And Error Amplifier 13. LX432 In 3.3V To 2.7V Low Dropout Regulator Application 4 Copyright © 1999 Rev. 1.0 9/99 PRODUCT DATABOOK 1996/1997 LX432 L OW V OLTAGE A DJUSTABLE P RECISION S HUNT R EGULATORS P RODUCTION D ATA S HEET CHARACTERISTIC CURVES 1.25 0.2 VREF : Reference Voltage (V) IREF : Reference Current ( A) 0.16 1.245 0.12 1.24 0.08 1.235 0.04 1.23 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 TJ : Junction Temperature ( C) TJ : Junction Temperature ( C) FIGURE 1 — Reference Voltage vs. Junction Temperature FIGURE 2 — Reference Current vs. Junction Temperature 800 700 -1.200 IK : Cathode Current ( A) 600 -1.000 400 300 200 100 0 -100 -200 -1 -0.5 0 0.5 1 1.5 ∆VREF /∆VKA (mV/V) 500 -0.800 -0.600 -0.400 -0.200 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 TJ : Junction Temperature (V) TJ : Junction Temperature ( C) FIGURE 3 — Cathode Current vs. Cathode Voltage FIGURE 4 — ∆VREF / ∆VKA vs. Junction Temperature Copyright © 1999 Rev. 1.0 9/99 5 PRODUCT DATABOOK 1996/1997 LX432 L OW V OLTAGE A DJUSTABLE P RECISION S HUNT R EGULATORS P RODUCTION D ATA S HEET CHARACTERISTIC CURVES 1.000 120 Dynamic Impedance (Ohm) 0.800 Minimum Cathode Current ( A) 100 80 0.600 60 0.400 40 0.200 20 0.000 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 TJ : Junction Temperature ( C) TJ : Junction Temperature ( C) FIGURE 5 — Dynamic Impedance vs. Junction Temperature FIGURE 6 — Minimum Cathode Current for Regulation vs. Junction Temperature 0.012 350 0.010 Noise Voltage (nV/sqrt(Hz)) -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 Off-State Current ( A) 300 0.008 0.006 250 0.004 200 0.002 0.000 150 10 100 1K 10K 100K TJ : Junction Temperature ( C) Frequency (Hz) FIGURE 7 — Off-State Current vs. Junction Temperature FIGURE 8 — Equivalent Input Noise Voltage vs. Frequency 6 Copyright © 1999 Rev. 1.0 9/99 PRODUCT DATABOOK 1996/1997 LX432 L OW V OLTAGE A DJUSTABLE P RECISION S HUNT R EGULATORS P RODUCTION D ATA S HEET PA R A M E T E R M E A S U R E M E N T I N F O R M AT I O N Input IK VKA Input IK VKA R1 IREF VREF R2 VREF FIGURE 9 — Test Circuit For VKA = VREF FIGURE 10 — Test Circuit For VKA > VREF Input IOFF VKA FIGURE 11 — Test Circuit For IOFF Copyright © 1999 Rev. 1.0 9/99 7 PRODUCT DATABOOK 1996/1997 LX432 L OW V OLTAGE A DJUSTABLE P RECISION S HUNT R EGULATORS P RODUCTION D ATA S HEET T Y P I C A L A P P L I C AT I O N VIN 110/220V AC VOUT 3.3V Controller UC384x/LX155x DRV V CC ISENSE GND VFB LX432 FIGURE 12 — LX432 In A Power Supply Isolated Feedback Application 12V 3 .3 V 0 .1 µ F 5009 1409 470µF 0 .1 µ F ( e .g . In te l i7 4 0 2 .7 V ® c h ip s e t) LX432 1209 1000µF 0 .1 µ F FIGURE 13 — LX432 In 3.3V To 2.7V Low Dropout Regulator Application PRODUCTION DATA - Information contained in this document is proprietary to LinFinity, and is current as of publication date. This document may not be modified in any way without the express written consent of LinFinity. Product processing does not necessarily include testing of all parameters. Linfinity reserves the right to change the configuration and performance of the product and to discontinue product at any time. 8 Copyright © 1999 Rev. 1.0 9/99