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Target Specification This is preliminary information on a new product foreseen to be developed. Details are subject to change without notice. March 2007 Rev 1 1/18 18 TSC101 High side current sense amplifier Features ■ Independent supply and input common-mode voltages ■ Wide common-mode operating range: 2.8 to 30V ■ Wide common-mode surviving range: -0.3 to 60V (load-dump) ■ Wide supply voltage range: 4 to 28V ■ Low current consumption: ICC max = 300µA ■ Internally fixed gain: 20V/V, 50V/V or 100V/V ■ Buffered output Applications ■ Battery chargers ■ Automotive current monitoring ■ Notebook computers ■ DC motor control ■ Precision current sources Description The TSC101 measures a small differential voltage on a high-side shunt resistor and translates it into a ground-referenced output voltage. The gain is internally fixed. Wide input common-mode voltage range, low quiescent current, and tiny SOT23 packaging enable use in a wide variety of applications. Input common-mode and power supply voltages are independent. Common-mode voltage can range from 2.8V to 30V in operating conditions and up to 60V in absolute maximum ratings. Current consumption lower than 300µA and wide supply voltage range allow to connect the power supply to either side of the current measurement shunt with minimal error. L SOT23-5 (Plastic package) 2 1 3Vp Out Gnd 4 5 Vm Vcc Pin connections (top view) www.st.com Contents TSC101 2/18 Contents 1 Application schematic and pin description . . . . . . . . . . . . . . . . . . . . . . 3 2 Absolute maximum ratings and operating conditions . . . . . . . . . . . . . 4 3 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4 Parameter definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Common mode rejection ratio (CMR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Supply voltage rejection ratio (SVR). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Gain (Av) and input offset voltage (Vos) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Output voltage drift versus temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Output voltage accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Output voltage range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 5 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 6 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 7 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 TSC101 Application schematic and pin description 3/18 1 Application schematic and pin description The TSC101 high-side current-sense amplifier features a 2.8V to 30V input common-mode range that is independent of supply voltage. The main advantage of this feature is to allow high-side current sensing at voltages much greater than the supply voltage (VCC). Figure 1. Application schematic Table 1 below describes the function of each pin. Their position is shown in the illustration on the cover page and in Figure 1 above. Table 1. Pin description Symbol Type Function Out Analog output The OUT voltage is proportional to the magnitude of the sense voltage Vp-Vm. Gnd Power supply Ground line. VCC Power supply Positive power supply line. Vp Analog input Connection for the external sense resistor. The measured current enters the shunt on the Vp side. Vm Analog input Connection for the external sense resistor. The measured current exits the shunt on the Vm side. Vsense Vout=Av.Vsense 43 1 2 Vp Vm Out Gnd 5 VCC load Iload2.8V to 30V Rg1 Rg2 Rg3 Rsense Absolute maximum ratings and operating conditions TSC101 4/18 2 Absolute maximum ratings and operating conditions Table 2. Absolute maximum ratings Symbol Parameter Value Unit Vid Input pins differential voltage (Vp-Vm) ±60 V Vi Input pin voltages (Vp, Vm)(1) 1. Voltage values are measured with respect to the GND pin. -0.3 to 60 V VCC DC supply voltage(1) -0.3 to 30 V Vout DC output pin voltage(1) -0.3 to 28 V Tstg Storage temperature -55 to 150 °C Tj Maximum junction temperature 150 °C ESD(2) 2. ESD test for each couple of pins. Human body model (HBM) 2 kV Machine model (MM) 200 V Table 3. Operating conditions Symbol Parameter Value Unit VCC DC supply voltage from Tmin to Tmax 4.0 to 28 V Toper Operational temperature range (Tmin to Tmax) -40 to 125 °C Rthja SOT23-5 thermal resistance junction to ambient 250 °C/W TSC101 Electrical characteristics 5/18 3 Electrical characteristics The electrical characteristics given in the following tables are measured under the following test conditions unless otherwise specified: Tamb=25°C, VCC=12V, Vsense=Vp-Vm=50mV, Vm=12V, no load on Out Table 4. Supply Symbol Parameter Test conditions Min. Typ. Max. Unit ICC Total supply current Vsense = 0 Tmin < Tamb < Tmax 300 µA Table 5. Input Symbol Parameter Test conditions Min. Typ. Max. Unit Vicm Common mode voltage range Tmin < Tamb < Tmax 2.8 30 V DC CMR DC common mode rejection Variation of Vout versus Vicm referred to input(1) 2.8V< Vicm < 30V Tmin < Tamb < Tmax 90 105 dB AC CMR AC common mode rejection Variation of Vout versus Vicm referred to input (peak-to-peak voltage variation) 2.8V< Vicm < 30V 1kHz sine wave 95 dB 2.8V< Vicm < 30V 10kHz sine wave 80 dB SVR Supply voltage rejection Variation of Vout versus VCC(2) 4.0V< VCC < 28V Vsense=30mV Tmin < Tamb < Tmax 90 105 dB Vos Input offset voltage(3) Tamb=25° C Tmin < Tamb < Tmax ±0.2 ±0.9 ±1.5 ±2.3 mV dVos/dT Input offset drift vs. T Tmin < Tamb < Tmax 0 4.5 µV/°C Ilk Input leakage current VCC=0V Tmin < Tamb < Tmax 1 µA Iib Input bias current Vsense=0V Tmin < Tamb < Tmax 5.5 8 µA 1. See Section 4: Parameter definitions on page 8 for the definition of CMR. 2. See Section 4: Parameter definitions on page 8 for the definition of SVR. 3. See Section 4: Parameter definitions on page 8 for the definition of Vos. Electrical characteristics TSC101 6/18 Table 6. Output Symbol Parameter Test conditions Min. Typ. Max. Unit Av Gain TSC101A TSC101B TSC101C 20 50 100 V/V ΔAv Gain accuracy Tamb=25°CTmin < Tamb < Tmax ±3 ±5 % ΔVout/ΔT Output voltage drift vs. T(1) Tmin < Tamb < Tmax -600 -300 0 µV/°C ΔVout/ΔIout Output stage load regulation -10mA < Iout <1 0mA Iout sink or source current 2 tbd mV/mA ΔVout Total output voltage accuracy(2) Vsense=10mV Tamb=25° C Tmin < Tamb < Tmax tbd tbd % ΔVout Total output voltage accuracy Vsense=20mV Tamb=25° C Tmin < Tamb < Tmax tbd tbd % ΔVout Total output voltage accuracy Vsense=50mV Tamb=25° C Tmin < Tamb < Tmax tbd tbd % ΔVout Total output voltage accuracy Vsense=100mV Tamb=25° C Tmin < Tamb < Tmax tbd tbd % Isc Short-circuit current OUT connected to VCC or GND 15 40 mA VOH Output stage high-state saturation voltage VOH=VCC-Vout Vsense=1V Iout=1mA 0.8 1 V VOL Output stage low-state saturation voltage Vsense=-1V Iout=1mA 50 100 mV 1. See Section 4: Parameter definitions on page 8 for the definition of output voltage drift versus temperature. 2. Output voltage accuracy is the difference with the expected theoretical output voltage Vout-th=Av*Vsense. See Section 4: Parameter definitions on page 8 for a more detailed definition. TSC101 Electrical characteristics 7/18 Table 7. Frequency response Symbol Parameter Test conditions Min. Typ. Max. Unit ts Output settling to 1% final value Vsense=10mV to 100mV, Cload=47pF TSC101A 3 µs TSC101B 6 µs TSC101C 10 µs SR Slew rate Vsense=10mV to 100mV 0.55 0.9 V/µs BW 3dB bandwidth Cload=47pF Vicm=12V Vsense=100mV TSC101A 650 kHz TSC101B 710 kHz TSC101C 540 kHz Table 8. Noise Symbol Parameter Test conditions Min. Typ. Max. Unit Total output voltage noise 50 nV/√ Hz Parameter definitions TSC101 8/18 4 Parameter definitions Common mode rejection ratio (CMR) The common-mode rejection ratio (CMR) measures the ability of the current-sensing amplifier to reject any DC voltage applied on both inputs Vp and Vm. The CMR is referred back to the input so that its effect can be compared with the applied differential signal. The CMR is defined by the formula: Supply voltage rejection ratio (SVR) The supply-voltage rejection ratio (SVR) measures the ability of the current-sensing amplifier to reject any variation of the supply voltage VCC. The SVR is referred back to the input so that its effect can be compared with the applied differential signal. The SVR is defined by the formula: CMR 20– ΔVout ΔVicm Av⋅ ------------------------------log⋅= SVR 20– ΔVout ΔVCC Av⋅ ------------------------------log⋅= TSC101 Parameter definitions 9/18 Gain (Av) and input offset voltage (Vos) The input offset voltage is defined as the intersection between the linear regression of Vout vs. Vsense curve with the X-axis (see Figure 2). If Vout1 is the output voltage with Vsense=Vsense1=50mV and Vout2 is the output voltage with Vsense=Vsense2=5mV, then Vos can be calculated with the following formula: The amplification gain Av is defined as the ratio between output voltage and input differential voltage: Figure 2. Vout versus Vsense characteristics: detail for low Vsense values Vos Vsense1 Vsense1 Vsense2– Vout1 Vout2– ------------------------------------------------ Vout1⋅⎝ ⎠⎛ ⎞–= Av Vout Vsense ------------------= V0 5mV 50mV Vsense Vout Parameter definitions TSC101 10/18 Output voltage drift versus temperature The output voltage drift versus temperature is defined as the maximum variation of Vout with respect to its value at 25°C, over the temperature range.It is calculated as follows: with Tmin < Tamb < Tmax. Figure 3 provides a graphical definition of output voltage drift versus temperature. On this chart, Vout is always comprised in the grey area defined by the maximum and minimum variation of Vout vs. T, and T=25°C is considered to be the reference. Figure 3. Output voltage drift versus temperature ΔVout ΔT----------------- max Vout Tamb( ) Vout 25° C( )– Tamb 25° C– --------------------------------------------------------------------------= Output voltage drift vs. temperature 4.44 4.46 4.48 4.5 4.52 4.54 4.56 4.58 -50 -25 0 25 50 75 100 125 Temperature (°C) V o u t (V ) TSC101 Parameter definitions 11/18 Output voltage accuracy The output voltage accuracy is the difference between the actual output voltage and the theoretical output voltage. Ideally, the current sensing output voltage should be equal to the input differential voltage multiplied by the theoretical gain, as in the following formula: Vout-th=Av . Vsense The actual value is very slightly different, mainly due to the effects of: ● the input offset voltage Vos, ● non-linearity, ● VOL and VOH voltage saturation (see Figure 5 on page 12) Figure 4. Vout vs. Vsense theoretical and actual characteristics The output voltage accuracy, expressed in percentage, can be calculated with the following formula: with Av=20V/V for TSC101A, Av=50V/V for TSC101B and Av=100V/V for TSC101C. Vsense Vout 5mV ideal actual ΔVout abs Vout Av Vsense⋅( )–( ) Av Vsense⋅ ---------------------------------------------------------------------------= Parameter definitions TSC101 12/18 Output voltage range The output voltage versus input differential voltage is linear in a range of output voltage limited by high-level and low-level saturation voltage. Figure 5. Vout vs. Vsense over the full voltage range Vsense Vout VCC VOH VOL TSC101 Application information 13/18 5 Application information TSC101 can be used to measure current and to feed back the information to a micro controller, as shown in Figure 6 below. Figure 6. Typical application schematic The current from the supply flows to the load through the Rsense resistor causing a voltage drop equal to Vsense across Rsense. The amplifier input currents are negligible, therefore its inverting input voltage is equal to Vm. The amplifier's open-loop gain forces its non-inverting input to the same voltage as the inverting input. As a consequence, the amplifier will adjust current flowing through Rg1 so that the voltage drop across Rg1 will exactly match Vsense. Therefore, the drop across Rg1 is: VRg1=Vsense=Rsense.Iload If IRg1 is the current flowing through Rg1, then IRg1 is given by the formula: IRg1=Vsense/Rg1 The IRg1 current flows entirely into resistor Rg3 (the input bias current of the buffer is negligible). Therefore, the voltage drop on the Rg3 resistor can be calculated as follows: VRg3=Rg3.IRg1=(Rg3/Rg1).Vsense 5V Vsense Vout load Iload 2.8V to 30V Rsense Vreg Vp V Out GND VCC Rg1 Rg2 Rg3 TSC101 Microcontroller ADC GND VCC Application information TSC101 14/18 Because the voltage across the Rg3 resistor is buffered to the Out pin, Vout can be expressed as: Vout=(Rg3/Rg1).Vsense or Vout=(Rg3/Rg1).Rsense.Iload The resistor ratio Rg3/Rg1 is internally set to 20V/V for TSC101A, to 50V/V for TSC101B and to 100V/V for TSC101C. Because they define the full scale output range of your application, the Rsense resistor and the Rg3/Rg1 resistor ratio (equal to Av) are important parameters, and therefore must be selected carefully. TSC101 Package information 15/18 6 Package information In order to meet environmental requirements, STMicroelectronics offers these devices in ECOPACK® packages. These packages have a lead-free second level interconnect. The category of second level interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an STMicroelectronics trademark. ECOPACK specifications are available at: www.st.com. Figure 7. SOT23-5 package Ref. Dimensions Millimeters Mils Min. Typ. Max. Min. Typ. Max. A 0.90 1.45 35.4 57.1 A1 0.00 0.15 0.00 5.9 A2 0.90 1.30 35.4 51.2 b 0.35 0.50 13.7 19.7 C 0.09 0.20 3.5 7.8 D 2.80 3.00 110.2 118.1 E 2.60 3.00 102.3 118.1 E1 1.50 1.75 59.0 68.8 e 0.95 37.4 e1 1.9 74.8 L 0.35 0.55 13.7 21.6 Ordering information TSC101 16/18 7 Ordering information Table 9. Order codes Part number Temperature range Package Packaging Marking Gain TSC101AILT -40°C, +125°C SOT23-5 Tape & reel O104 20 TSC101BILT O105 50 TSC101CILT O106 100 TSC101AIYLT(1) -40°C, +125°C automotive grade SOT23-5 Tape & reel O101 20 TSC101BIYLT(1) O102 50 TSC101CIYLT(1) O103 100 1. Qualified and characterized according to AEC Q100 and Q003 or equivalent, advanced screening according to AEC Q001 & Q 002 or equivalent. TSC101 Revision history 17/18 8 Revision history Date Revision Changes 5-Mar-2007 Rev 1 First release, preliminary data. TSC101 18/18 Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. 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Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any liability of ST. ST and the ST logo are trademarks or registered trademarks of ST in various countries. Information in this document supersedes and replaces all information previously supplied. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners. © 2007 STMicroelectronics - All rights reserved STMicroelectronics group of companies Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan - Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America www.st.com 1 Application schematic and pin description Figure 1. Application schematic Table 1. Pin description 2 Absolute maximum ratings and operating conditions Table 2. Absolute maximum ratings Table 3. Operating conditions 3 Electrical characteristics Table 4. Supply Table 5. Input Table 6. Output Table 7. Frequency response Table 8. Noise 4 Parameter definitions Common mode rejection ratio (CMR) Supply voltage rejection ratio (SVR) Gain (Av) and input offset voltage (Vos) Figure 2. Vout versus Vsense characteristics: detail for low Vsense values Output voltage drift versus temperature Figure 3. Output voltage drift versus temperature Output voltage accuracy Figure 4. Vout vs. Vsense theoretical and actual characteristics Output voltage range Figure 5. Vout vs. Vsense over the full voltage range 5 Application information Figure 6. Typical application schematic 6 Package information Figure 7. SOT23-5 package 7 Ordering information Table 9. Order codes 8 Revision history