SILICON LABS TS1105 Current Sense Amplifier User Guide

TS1105 Current Sense Amplifier

Product Information

TS1105/06/09 Current Sense Amplifier EVB User’s Guide

The TS1105, TS1106, and TS1109 are high-side current sense amplifiers (CSA) that come with a buffered output that has an adjustable bias. The TS1109 bidirectional CSA buffered output uses a bipolar scheme with respect to the bias voltage, while the TS1106 bidirectional CSA buffered output uses a unipolar scheme. These amplifiers are designed to provide accurate current sensing in a variety of applications.

Key Features

• High-side current sense amplifier (CSA)
• Buffered output with adjustable bias
• Bidirectional CSA buffered output (TS1109)
• Unipolar CSA buffered output (TS1106)

Ordering Information

To order the TS1105/06/09 Current Sense Amplifier EVB, visit silabs.com or Arrow.com.

Product Usage Instructions

Quick Start Procedure

1. Connect the components as shown in Figure 2.1.
2. Apply a voltage between 4.5V and 60V to the V+ and GND pins.
3. Connect a load to the ILOAD pins.
4. Set the voltage on JP3 to 1V.
5. Set the voltage on JP4 to 0V.
6. To evaluate the bidirectional functionality and observe the unipolar or bipolar CSA buffered output, set the voltage on JP5 to 2V for TS1106 or 1V for TS1109.

Output Voltages by Part Number

Note: VOUT should equal 1V, and SIGN should be HIGH.

TS1105 and TS1106 Output Voltage Equation

VOUT = (ILOAD x RS) + VB, where RS is the sense resistor value, and VB is the bias voltage.

TS1109 Output Voltage Equation

VOUT = (ILOAD x RS) + (VB x SIGN), where RS is the sense resistor value, VB is the bias voltage, and SIGN is a binary signal that controls the direction of the output voltage.

TS1105/06/09 Current Sense Amplifier EVB User’s Guide

The TS1105, TS1106, and TS1109 combine a high-side current sense amplifier (CSA) with a buffered output featuring an adjustable bias. The TS1109 bidirectional CSA buffered output uses a bipolar scheme with respect to the bias voltage, while the TS1106 bidirectional CSA buffered output uses a unipolar scheme.

The TS1105/06/09 CSA requires a very low 0.68 µA supply current, while the CSA buffered output requires a very low nominal supply current of 0.76 µA. These CSAs are de-signed for high precision current measurements as the TS1109 combines a 1% gain error(MAX) with a 150 µV VOS(MAX) while the TS1105/06 combine a 0.6% gain error(MAX) with a 100 µV VOS(MAX) . The inverting terminal of the CSA output buffer, FILT, is also made accessible so that a RC Filter can be connected to reduce noise.

The TS1105/06/09 is fully specified to operate over the –40 °C to +85 °C temperature range and is available in a low-profile, thermally-enhanced, 8-pin 3 x 3 mm TDFN pack-age with an exposed back-side paddle.

KEY FEATURES

• RSENSE: 50 mΩ ± 0.5%
• Adjustable Bias for CSA Buffer
• Compatible for Both Gain Options
• 20 V/V
• 200 V/V

ORDERING INFORMATION

• TS1105-20DB
• TS1105-200DB
• TS1106-20DB
• TS1106-200DB
• TS1109-20DB
• TS1109-200DB

Description

The TS1105/06/09 Evaluation Board is intended for evaluation of the current sense amplifier plus the buffered output with adjustable bias. The evaluation board includes a variable reference scheme so that the bias voltage of the CSA buffered output can be adjusted with respect to the VDD voltage. The jumpers, JP2 and JP3, can be connected so that the included potentiometer can be used to adjust the bias voltage. The Quick Start Procedure details adjustment of the bias voltage for the CSA buffered output and measurement of the output voltage for a given load.

Table 1.1. Component List

TS1109-20, TS1109-200

R1| 1| 4.02 kΩ ± 1%, 1/16 W (0603)
R2| 1| 0.05 Ω ± 0.5%,1/2 W (1206)
C1, C6| 2| 1 µF ± 10%, 10 V (0603)
C2, C10| 2| 0.1 µF ± 10%, 10 V (0603)
C5| 1| 0.47 µF ± 10%, 10 V (0603)
J1, J2, J3, J4| 4| Header 1 x 1
J5 (TS1106 and TS1109 Only)| 1| Header 1 x 1
JP1, JP2, JP3, JP4, JP5| 5| Header 1 x 2
JS1, JS2| 2| Jumper Shunt

Quick Start Procedure

Required Equipment

• 3 V Power Supply or 3 V Battery
• 2 Digital Multimeters
• 1 ammeter
• 1 voltmeter
• Potentiometer

To use the TS1105/06/09 evaluation board, perform the following steps:

1. Configure JP3 so that the Jumper Shunt is connecting VDD to EXT_REF_1, and configure JP2 so that the jumper shunt is con-necting VBIAS to EXT_REF_2.

2. Connect the 3 V power source to RS+ and VDD.

3. Use the voltmeter to measure the VBIAS voltage, and adjust P1 potentiometer so that VBIAS is 1.5 V.

4. Connect the voltmeter to measure VOUT. With no load connected, VOUT should be equal to VBIAS. The expression for the VOUT output voltage is defined by the following equations:
   VOUT = VVBIAS − (GAIN × RSENSE × | iSENSE | )
   Equation 1. TS1105 and TS1106 Output Voltage
   VOUT = VVBIAS − (GAIN × RSENSE × ± iSENSE) Equation 2. TS1109 Output Voltage

5. Connect an ammeter in series from RS– to a potentiometer. Adjust the POT until the ammeter reads:

   • TS1105/06/09-20: 500 mA
   • TS1105/06/09-200: 50 mA
     VOUT should equal 1 V, and SIGN should be HIGH.

6. TS1106 and TS1109 Only: To evaluate the bidirectional functionality and observe the unipolar or bipolar CSA buffered output scheme, disconnect the 3 V power supply from RS+ and VDD, as well as the POT connected to RS–. Reconfigure the 3 V power source by connecting it to RS– and VDD. Connect the ammeter in series from RS+ to the potentiometer. Adjust the POT so that the ammeter reads the correct ILOAD value for the given part number. The SIGN output will be LOW. Confirm that the output volt-age matches with the given part number.

Table 2.1. Output Voltages by Part Number

Figure 2.1. TS1105/06/09DB Circuit Schematic

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Silicon Laboratories intends to provide customers with the latest, accurate, and in-depth documentation of all peripherals and modules available for system and software implementers using or intending to use the Silicon Laboratories products. Characterization data, available modules and peripherals, memory sizes and memory addresses refer to each specific device, and “Typical” parameters provided can and do vary in different applications. Application examples described herein are for illustrative purposes only. Silicon Laboratories reserves the right to make changes without further notice and limitation to product information, specifications, and descriptions herein, and does not give warranties as to the accuracy or completeness of the included information. Silicon Laboratories shall have no liability for the consequences of use of the information supplied herein. This document does not imply or express copyright licenses granted hereunder to design or fabricate any integrated circuits. The products must not be used within any Life Support System without the specific written consent of Silicon Laboratories. A “Life Support System” is any product or system intended to support or sustain life and/or health, which, if it fails, can be reasonably expected to result in significant personal injury or death. Silicon Laboratories products are generally not intended for military applications. Silicon Laboratories products shall under no circumstances be used in weapons of mass destruction including (but not limited to) nuclear, biological or chemical weapons, or missiles capable of delivering such weapons.

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