A M I C R O S E M I LX432 Low Voltage Adjustable Precision Shunt Regulator C O M P A N Y P RODUCTION D ATA S HEET 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 12. 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. W W W . Microsemi . COM 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 – typical output impedance is 200mΩ. The LX432 series operates with an operating current as low as 80µA, making these devices suitable for portable and micropower applications. 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 Sink Current Capability 80µA To 20mA Direct Alternative To TLV431 IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com Low Voltage Adjustable Power Supplies Instrumentation Computers Portable Equipment V IN V KA R1 C athode R eference LX432 A node R2 GND LX432 SC / SE TA (°C) Package Marking 0 to 70 -40 to 85 432C 432I SC Plastic SOT-23 3-Pin LX432CSC LX432ISC SE Plastic SOT-23 5-Pin LP LX432CSE LX432ISE Plastic TO-92 3-Pin LX432CLP LX432ILP Note: Available in Tape & Reel. Append the letter “T” to the part number. (i.e. LX432CSET) TO-92 (LP) package also available in ammo-pack. Copyright 2000 Rev. 1.2c, 2001-04-11 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 A M I C R O S E M I LX432 Low Voltage Adjustable Precision Shunt Regulator C O M P A N Y P RODUCTION D ATA S HEET 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 ............................................................................... 150°C Storage Temperature.................................................................................... -65ºC to 150°C Lead Temperature...................................................................................................... 300°C REF 3 C A T HO D E 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 specified terminal. SC 3-Pin Plastic Package A NO D E 2 SC PACKAGE – 3-PIN N .C . 1 N .C . 2 CATHODE 3 5 ANODE 4 REF N .C . - N o Inte rna l C on ne ctio n Thermal Resistance – Junction to Ambient, θJA SE 1 W W W . Microsemi . COM (PC Mounted) 220°C/W (Non-PC Mounted) 410°C/W 5-Pin Plastic Package SE PACKAGE – 5-PIN 3. C A T H O D E Thermal Resistance – Junction to Ambient, θJA (PC Mounted) 220°C/W (Non-PC Mounted) 410°C/W 2. A N O D E 1. R E F LP 3-Pin Plastic Package Thermal Resistance – Junction to Ambient, θJA 156°C/W 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. LP PACKAGE – 3-PIN (All Views Top View) Cathode (K ) + Ref(R) PACKAGE DATA V REF Anode(A) Figure 1 – Simplified Block Diagram Copyright 2000 Rev. 1.2c, 2001-04-11 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 2 A M I C R O S E M I LX432 Low Voltage Adjustable Precision Shunt Regulator C O M P A N Y P RODUCTION D ATA S HEET Unless otherwise specified, the following specifications apply over the operating ambient temperature for the LX432C with 0°C 70°C and the LX432I with -40°C < TA < 85°C except where otherwise noted. Parameter Symbol Reference Voltage Reference Voltage Drift (note 2) REF 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 Ratio of VREF Change In Cathode Voltage Change (note 3) REF KA IK = 10ma, VKA = VREF to 16V, TA = 25°C Reference Terminal Current Reference Current Drift (note 2) Minimum Cathode Current For Regulation Dynamic Impedance Off-State Cathode Current VREF Test Conditions REF 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 IK(MIN) VKA = VREF, TA = 25°C IREF ZKA IOFF Min 1.228 IK = 0.1mA to 15mA, VKA = VREF, TA = 25°C VKA = 16V, TA = 25°C ≤ TA ≤ LX432 Typ 1.24 3 4 Max 1.252 12 20 -1 -2.7 mV/V 0.1 0.5 µA 0.05 0.1 0.3 0.4 µA µA 55 80 µA 0.2 0.004 0.4 Ω µA Units V mV mV W W W . Microsemi . COM Note 2: These parameters are guaranteed by design. Note 3: REF KA Ratio of change in reference input voltage to the change in cathode voltage ELECTRICALS Copyright 2000 Rev. 1.2c, 2001-04-11 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 3 A M I C R O S E M I LX432 Low Voltage Adjustable Precision Shunt Regulator C O M P A N Y P RODUCTION D ATA S HEET W W W . Microsemi . COM STABILITY BOUNDARY CONDITION† 30 Unstable 25 IK Cathode Current (mA) VKA = 2V 20 Stable 15 VKA = 3V 10 5 VKA = VREF * 0 0.001 0.010 0.100 1.000 10.000 CL- Load Capacitance (uF) Figure 2 – Stability * Unstable below 700µA as indicated † The unstable areas indicate loading conditions that may cause the device to oscillate. STABILITY Copyright 2000 Rev. 1.2c, 2001-04-11 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 4 A M I C R O S E M I LX432 Low Voltage Adjustable Precision Shunt Regulator C O M P A N Y P RODUCTION D ATA S HEET 1.242 W W W . Microsemi . COM 0.2 0.18 1.241 IREF: Reference Current(µA) V REF: Reference Voltage (V) 0.16 1.24 1.239 1.238 1.237 1.236 0.14 0.12 0.1 0.08 0.06 0.04 0.02 1.235 -50 0 25 50 75 100 0 -50 125 TJ: Junction Temperature (°C) 0 25 50 75 100 125 TJ: Junction Temperature (°C) Figure 3 – Reference Voltage vs. Junction Temperature Figure 4 – Reference Current vs. Junction Temperature 900 -1.2 800 -1 REF KA (mV/V) 600 500 400 300 200 -0.8 -0.6 CHARACTERISTICS IK: Cathode Current (µA) 700 -0.4 100 -0.2 0 1.5 1.25 1 0.75 0.5 0.25 0 -0.3 -0.5 -0.8 -1 -100 Cathode Voltage (V) 0 25 50 75 100 125 TJ: Junction Temperature (°C) Figure 5 – Cathode Current vs. Cathode Voltage Copyright 2000 Rev. 1.2c, 2001-04-11 0 -50 Figure 6 – REF KA vs. Junction Temperature Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 5 A M I C R O S E M I LX432 Low Voltage Adjustable Precision Shunt Regulator C O M P A N Y P RODUCTION D ATA S HEET 0.8 W W W . Microsemi . COM 120 Minimum Cathode Current (µA) Dynamic Impedance (ohm) 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 -50 0 25 50 75 100 80 60 40 20 0 -50 125 0 25 50 75 100 125 TJ: Junction Temperature (°C) TJ: Junction Temperature (°C) Figure 7 – Dynamic Impedance vs. Junction Temperature Figure 8 – Minimum Cathode Current for Regulation vs. Junction Temperature 0.07 350 0.06 300 Noise Voltage (nV/sqrt(Hz)) Off-State Current (µA) 100 0.05 0.04 0.03 0.02 0.01 150 100 50 0 0 25 70 85 125 10 100 1K 10K 100K Frequency (Hz) TJ: Junction Temperature (°C) Figure 9 – Off-State Current vs. Junction Temperature Copyright 2000 Rev. 1.2c, 2001-04-11 200 Figure 10 – Equivalent Input Noise Voltage vs. Frequency Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 6 CHARACTERISTICS 0 -50 250 A M I C R O S E M I LX432 Low Voltage Adjustable Precision Shunt Regulator C O M P A N Y P RODUCTION D ATA S HEET W W W . Microsemi . COM V KA In pu t IK V REF Figure 11 – Test Circuit For VKA = VREF V KA Input V KA Input I O FF IK R1 I REF R2 V REF Figure 12 – Test Circuit For VKA > VREF Copyright 2000 Rev. 1.2c, 2001-04-11 R1 + IREF × R1 R2 MEASUREMENT VO = VKA = VREF × 1 + Figure 13 – Test Circuit For IOFF Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 7 A M I C R O S E M I LX432 Low Voltage Adjustable Precision Shunt Regulator C O M P A N Y P RODUCTION D ATA S HEET V IN 11 0 / 2 20V A C _ V OUT 3.3V + + + W W W . Microsemi . COM DRV V CC C o n tro lle r U C384x / LX155x ISEN SE GND V FB + + LX432 Figure 12 – LX432 In A Power Supply Isolated Feedback Application 12V 3.3V 470µ F 0.1µ F 0.1µ F 500 Ω 140 Ω L X 4 32 2.7V 120 Ω 1000µ F APPLICATIONS (e .g. In tel i74 0 chipset) 0.1µ F Figure 13 – LX432 in a 3.3V to 2.7V Low Dropout Regulator Application Copyright 2000 Rev. 1.2c, 2001-04-11 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 8 A M I C R O S E M I LX432 Low Voltage Adjustable Precision Shunt Regulator C O M P A N Y P RODUCTION D ATA S HEET SE W W W . Microsemi . COM 5 Pin Plastic SOT-23 D Dim F H A A1 B C D E F G H I J K E G A A1 C B SC J K I MILLIMETERS MIN MAX 0.90 1.30 0.90 1.45 0.25 0.50 0.09 0.20 2.80 3.10 1.50 1.75 0.95 BSC 1.90 BSC 2.60 3.00 0.35 0.55 0.00 0.15 10° MAX INCHES MIN MAX 0.035 0.051 0.035 0.057 0.010 0.020 0.004 0.008 0.110 0.122 0.059 0.069 0.038 BSC 0.075 BSC 0.102 0.118 0.014 0.022 0.000 0.006 10° MAX 3-Pin Plastic SOT-23 Dim D E H F G INCHES MIN MAX 0.035 0.044 0.015 0.020 0.003 0.007 0.110 0.120 0.047 0.055 0.035 0.043 0.070 0.080 0.083 0.104 0.014 0.022 0.0005 0.0039 Note: A B Copyright 2000 Rev. 1.2c, 2001-04-11 J I C 1. Dimensions do not include mold flash or protrusions; these shall not exceed 0.155mm(.006”) on any side. Lead dimension shall not include solder coverage. Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 9 MECHANICALS A B C D E F G H I J MILLIMETERS MIN MAX 0.89 1.12 0.37 0.51 0.085 0.18 2.80 3.04 1.20 1.40 0.89 1.09 1.78 2.05 2.10 2.64 0.35 0.55 0.013 0.10 A M I C R O S E M I LX432 Low Voltage Adjustable Precision Shunt Regulator C O M P A N Y P RODUCTION D ATA S HEET LP 3-Pin Plastic TO-92 Dim A J S E C T x-x B D x C V x N K N A B C D F G H J K N V MILLIMETERS MIN MAX 4.45 5.20 4.32 5.33 3.18 4.19 0.41 0.55 0.41 0.48 1.15 1.39 2.42 2.66 0.39 0.50 12.70 2.05 2.66 3.43 - INCHES MIN MAX 0.175 0.205 0.170 0.210 0.125 0.165 0.016 0.022 0.016 0.019 0.045 0.055 0.095 0.105 0.015 0.020 0.500 0.080 0.105 0.135 - W W W . Microsemi . COM F Note: 1. Dimensions do not include mold flash or protrusions; these shall not exceed 0.155mm(.006”) on any side. Lead dimension shall not include solder coverage. G H MECHANICALS Copyright 2000 Rev. 1.2c, 2001-04-11 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 10 A M I C R O S E M I LX432 Low Voltage Adjustable Precision Shunt Regulator C O M P A N Y P RODUCTION D ATA S HEET W W W . Microsemi . COM NOTES 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. Copyright 2000 Rev. 1.2c, 2001-04-11 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 11