TS1101 TOUCHSTONE | Alldatasheet

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© 2012 Touchstone Semiconductor, Inc. All rights reserved.

FEATURES

♦ Ultra-Low Supply Current: 1μA ♦ Wide Input Common Mode Range: +2V to +25V ♦ Low Input Offset Voltage: 100μV (max) ♦ Low Gain Error: 0.6% (max) ♦ Voltage Output ♦ SIGN Comparator Output: No “Dead Zone” at ILOAD Switchover ♦ Four Gain Options Available: TS1101-25: Gain = 25V/V TS1101-50: Gain = 50V/V TS1101-100: Gain = 100V/V TS1101-200: Gain = 200V/V ♦ 6-Lead SOT23 Packaging

APPLICATIONS

Portable/Battery-Powered Systems Smart Chargers Smart Phones

DESCRIPTION

The bi-directional, voltage-output TS1101 current- sense amplifiers are the lowest -power and most accurate current -sense amplifiers available today. Consuming a very low 1μA supply current, the TS1101 high-side curr ent-sense amplifiers exh ibit a 100-µV (max) VOS and a 0.6% (max) gain error, both specifications optimized for any precision current measurement. For all high -side bidirectional current- sensing applications, the TS1101s are self -powered and feature a wide input common -mode voltag e range from 2 V to 25V. A SIGN comparator digital output is also provided that indicates the direction of current flow depending on the external connections to the TS1101’s RS+ and RS- input terminals. The SOT23 package make s the TS1101 an ideal choice for pcb-area-critical, supply-current-conscious, high-accuracy current -sense applications in all battery-powered and portable instruments. All TS1101s are specified for operation over the -40°C to +105°C extended temperature range. A 1µA, +2V to +25V Bidirectional Precision Current-Sense Amplifier TYPICAL APPLICATION CIRCUIT PA\`RT GAIN OPTION TS1101-25 25 V/V TS1101-50 50 V/V TS1101-100 100 V/V TS1101-200 200 V/V The Touchstone Semiconductor logo is a registered trademark of Touchstone Semiconductor, Incorporated. SIGN Comparator’s Symmetric ILOAD Switchover

Continuous Power Dissipation (TA = +70°C) 6-Lead SOT23 (Derate at 4.5mW/°C above +70°C) Electrical and thermal s tresses beyond those lis ted under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other condition beyond those indicated in the operational sections of the specifications is not implied. Exposure to any absolute maximum rating conditions for extended periods may affect device reliability and lifetime. PACKAGE/ORDERING INFORMATION ORDER NUMBER PART MARKING CARRIER QUANTITY TS1101-25EG6TP TADN Tape & Reel ----- TS1101-25EG6T Tape & Reel 3000 TS1101-50EG6TP TADP Tape & Reel ----- TS1101-50EG6T Tape & Reel 3000 TS1101-100EG6TP TADQ Tape & Reel ----- TS1101-100EG6T Tape & Reel 3000 TS1101-200EG6TP TADR Tape & Reel ----- TS1101-200EG6T Tape & Reel 3000 Lead-free Program: Touchstone Semiconductor supplies only lead-free packaging. Consult Touchstone Semiconductor for products specified with wider operating temperature ranges.

ELECTRICAL CHARACTERISTICS

VRS+ = 3.6V; VSENSE = (VRS+ - VRS-) = 0V; COUT = 47nF; VDD = 1.8V; TA = -40°C to +105°C, unless otherwise noted. Typical values are at TA = +25°C. See Note 1. PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Current (Note 2) ICC TA = +25°C 0.68 0.85 μA 1.0 VRS+ = 25V TA = +25°C 1.0 1.2 Common-Mode Input Range VCM Guaranteed by CMRR 2 25 V CURRENT SENSE AMPLIFIER PARAMETERS Common-Mode Rejection Ratio CMRR 2V < VRS+ < 25V 120 150 dB Input Offset Voltage (Note 3) VOS TA = +25°C ±30 ±100 μV ±200 VOS Hysteresis (Note 4) VHYS TA = +25°C 10 µV Gain G TS1101-25 25 V/V TS1101-50 50 TS1101-100 100 TS1101-200 200 Gain Error (Note 5) GE TA = +25°C ±0.2 ±0.6 % ±1.0 Gain Match (Note 5) GM TA = +25°C ±0.2 ±0.6 % ±1 Output Resistance (Note 6) ROUT TS1101-25/50/100 7.0 10 13.2 kΩ TS1101-200 14.0 20 26.4 OUT Low Voltage VAOL Gain = 25 5 mV Gain = 50 10 Gain = 100 20 Gain = 200 40 OUT High Voltage (Note 7) VAOH VOH = VRS- - VOUT 0.05 0.2 V Output Settling Time tS TS1101-25/50/100 1% final value, VOUT = 3V 2.2 ms TS1101-200 4.3 ms SIGN COMPARATOR PARAMETERS VDD Supply Voltage Range VDD 1.25 5.5 V VDD Supply Current IDD 0.02 0.2 μA Output Low Voltage VCOL VDD = 1.25V, ISINK = 5µA 0.2 V VDD = 1.8V, ISINK = 35µA Output High Voltage VCOH VDD = 1.25V, ISOURCE = 5µA VDD – 0.2 V VDD = 1.8V, ISOURCE = 35µA Propagation Delay tPD VSENSE = ±1mV 3 ms VSENSE = ±10mV 0.4 Note 1: All devices are 100% production tested at TA = +25°C. All temperature limits are guaranteed by product characterization. Note 2: Extrapolated to VOUT = 0. ICC is the total current into the RS+ and the RS- pins. Note 3: Input offset voltage VOS is extrapolated from a VOUT+ measurement with VSENSE set to +1mV and a VOUT- measurement with VSENSE set to -1mV; vis-a-viz, Average VOS = VO T- - VO T+ x GAIN Note 4: Amplitude of VSENSE lower or higher than VOS required to cause the comparator to switch output states. Note 5: Gain error applies to current flow in either direction and is calculated by applying two values for VSENSE and then calculating the error of the actual slope vs. the ideal transfer characteristic: For GAIN = 25, the applied VSENSE is 20mV and 120mV. For GAIN = 50, the applied VSENSE is 10mV and 60mV. For GAIN = 100, the applied VSENSE is 5mV and 30mV. For GAIN = 200, the applied VSENSE is 2.5mV and 15mV. Note 6: The device is stable for any capacitive load at VOUT. Note 7: VOH is the voltage from VRS- to VOUT with VSENSE = 3.6V/GAIN.

Input Offset Voltage vs Common-Mode Voltage Supply Current vs Common-Mode Voltage Input Offset Voltage vs Temperature Supply Current vs Temperature PERCENT OF UNITS - % INPUT OFFSET VOLTAGE - µV PERCENT OF UNITS - % GAIN ERROR - % INPUT OFFSET VOLTAGE - µV TEMPERATURE - °C TEMPERATURE - °C SUPPLY CURENT - µA SUPPLY VOLTAGE - Volt 20 20 10 30 -10 40 25V 3.6V INPUT OFFSET VOLTAGE - µV SUPPLY VOLTAGE - Volt SUPPLY CURRENT - µA TYPICAL PERFORMANCE CHARACTERISTICS VRS+ = VRS- = 3.6V; TA = +25°C, unless otherwise noted. -40 -15 10 60 110 85 0 5 10 15 30 25 0.2 0.6 0.8 0.4 1 40 -20 -40 Input Offset Voltage Histogram Gain Error Histogram 35 20 0 5 10 15 30 25 20 0.2 0.6 0.8 0.4 -40 -15 10 60 110 85 35 50 -0.2 0.4

Gain Error vs Common-Mode Voltage SUPPLY VOLTAGE - Volt Gain Error vs. Temperature Small-Signal Gain vs Frequency SMALL-SIGNAL GAIN -dB VSENSE- mV COMMON-MODE REJECTION - dB 0.2 0.3 0.001 0.1 1 10 1000 -15 -35 -25 10 20 0 30 GAIN ERROR - % G = 100 G = 25 G = 50 G = 100 G = 50 G = 25 VOUT vs VSENSE @ Supply = 3.6V VOUT - V G = 25 G = 100 G = 50 G =25 G = 50, 100 FREQUENCY - kHz Common-Mode Rejection vs Frequency 0.1 -0.3 -0.2 0.1 0.2 0.3 -0.1 15 5 0 150 100 50 0 100 60 20 2.5 3.5 1.5 0.2 0.8 1.0 0.4 0.6 -10 -20 -30 100 -20 -60 -140 -80 -40 -100 -120 TYPICAL PERFORMANCE CHARACTERISTICS VRS+ = VRS- = 3.6V; TA = +25°C, unless otherwise noted. -40 -15 35 60 85 10 TEMPERATURE - °C GAIN ERROR - % VSENSE- mV VOUT - V VOUT vs VSENSE @ Supply = 2V FREQUENCY - kHz 40 80 1.2 1.8 1.4 1.6 0.5 25 110 0.01 0.001 0.1 1 10 1000 100 0.01 0.4

200µs/DIV 200µs/DIV Small-Signal Pulse Response, Gain = 100 VSENSE VOUT VSENSE VOUT TYPICAL PERFORMANCE CHARACTERISTICS VRS+ = VRS- = 3.6V; COUT = 0pF; TA = +25°C, unless otherwise noted. 200µs/DIV 200µs/DIV Small-Signal Pulse Response, Gain = 50 VSENSE VOUT VSENSE VOUT Large-Signal Pulse Response, Gain = 50 200µs/DIV 200µs/DIV Small-Signal Pulse Response, Gain = 25 VSENSE VOUT VSENSE VOUT Large-Signal Pulse Response, Gain = 25 Large-Signal Pulse Response, Gain = 100

1 GND Ground. Connect this pin to analog ground. 2 SIGN Comparator Output, push-pull; SIGN is HIGH for (VRS+ > VRS-) and LOW for (VRS- > VRS+). 3 OUT Output Voltage. VOUT is proportional to VSENSE = (VRS+ - VRS-) or (VRS- - VRS+).

4 RS- External Sense Resistor Load-Side Connection

5 VDD SIGN Comparator External Power Supply Pin; Connect this pin to system’s logic VDD supply.

6 RS+ External Sense Resistor Power-Side Connection

The internal configuration of the TS1101 – a bidirectional high-side, current-sense amplifier – is a variation of the TS1100 uni -directional current-sense amplifier. In the design of the TS1101, the input amplifier was reconfigured for fully differential input/output operation and a second low-threshold p- channel FET (M2) was added where the drain terminal of M2 is also connected to ROUT. Therefore, the behavior of the TS1101 for when VRS- > VRS+ is identical for when VRS+ > VRS-. Referring to the typical application circuit on Page 1, the inputs of the TS1101’s differential input/output amplifier are connected across an external RSENSE resistor that is used to measure current. At the non - inverting input of the TS1101 (the RS- terminal), the applied voltage is I LOAD x RSENSE. Since the RS - terminal is the non -inverting input of the internal op amp, op amp feed back action forces the inverting input of the internal op amp to the same potential (ILOAD x RSENSE). Therefore, the voltage drop across RSENSE (V SENSE = V RS+ - VRS-) and the voltage drop across R GAINA (at the RS+ terminal) are equal. Necessary for gain ra tio match, both RGAINA and RGAINB are the same value. Since p-channel M1’s source is connected to the inverting input of the internal op amp and since the voltage drop across R GAINA is the same as the

The other attribute of the SIGN comparator’s behavior is its propagation delay as a function of applied V SENSE [(VRS+ - VRS-) or (V RS- - VRS+)]. As shown in Figure , the SIGN comparator’s propagation dela y behavior is symmetric regardless of current-flow direction and is inversely proportional to VSENSE. APPLICATIONS INFORMATION Choosing the Sense Resistor Selecting the optimal value for the external RSENSE is based on the following criteria and for each commentary follows: 1) RSENSE Voltage Loss 2) VOUT Swing vs. Applied Input Voltage at VRS+ and Desired VSENSE 3) Total ILOAD Accuracy 4) Circuit Efficiency and Power Dissipation 5) RSENSE Kelvin Connections 1) RSENSE Voltage Loss For lowest IR power dissipation in RSENSE, the smallest usable resistor value for RSENSE should be selected. 2) VOUT Swing vs. Applied Input Voltage at VRS+ and Desired VSENSE As there is no separate power supply pin for the TS1101, the circuit draws its power from the voltage at its R S+ and RS - terminals. Therefore, the signal voltage at the OUT terminal is bounded by the minimum voltage applied at the RS+ terminal. Therefore, VOUT(max) = VRS+(min) - VSENSE(max) – VOH(max) and RS NS VO T max GAIN ILOAD max where the full -scale V SENSE should be less than VOUT(MAX)/GAIN at the application’s minimum RS+ terminal voltage. For best performance with a 3.6V power supply, RSENSE should be chosen to generate a VSENSE of: a) 120mV (for the 25V/V GAIN option), b) 60mV (for the 50V/V GAIN option), c) 30mV (for the 100V/V GAIN option), or d) 15mV (for the 200V/V GAIN option) at the full -scale I LOAD current in each application. For the case where the minimum power supply voltage is higher than 3.6V, each of the four full -scale VSENSEs above can be increased. 3) Total Load Current Accuracy In the TS1101’s linear region where VOUT < VOUT(max), there are two specifications related to the circuit’s accuracy: a the TS1101’s input offset voltage (V OS(max) = 100μV and b) its gain error (GE(max) = 0.6%). An expression for the TS1101’s total error is given by: VOUT = [GAIN x (1 ± GE) x VSENSE] ± (GAIN x VOS) A large value for RSENSE permits the use of smaller load currents to be measured more accurately because the effects of offset voltages are less significant when compared to larger VSENSE voltages. Due car e though should be exercised as previously mentioned with large values of RSENSE. 4) Circuit Efficiency and Power Dissipation IR losses in RSENSE can be large especially at high load currents. It is important to select the smallest, usable RSENSE value to minimize power dissipation and to keep the physical size of RSENSE small. If the external RSENSE is allowed to dissipate significant power, then its inh erent temperature coefficient may alter its design center value, thereby reducing load current measurement accuracy. Precisely because the TS1101’s input stage was designed to exhibit a very low input offset voltage , small RSENSE values can be used to reduce power dissipation and minimize local hot spots on the pcb. 5) RSENSE Kelvin Connections For optimal VSENSE accuracy in the presence of large load currents, parasitic pcb track resistance should be minimized. Kelvin -sense pcb connections between RSENSE and the TS1101’s RS+ and RS - terminals are strongly recommended. The drawing in Figure 3 illustrates the connections between

the current-sense amplifier and the current -sense resistor. The pcb layout should be balanced and symmetrical to minimize wiring -induced errors. In addition, the pcb layout for RSENSE should include good thermal management techniques for optimal RSENSE power dissipation. 6) RSENSE Composition Current-shunt resistors are available in metal film, metal strip, and wire -wound constr uctions. Wire - wound current -shunt resistors are constructed with wire spirally wound onto a core. As a result, these types of current shunt resistors exhibit the largest self inductance. In applications where the load current contains high -frequency transi ents, metal film or metal strip current sense resistors are recommended. Internal Noise Filter In power management and motor control applications, current-sense amplifiers are required to measure load currents accurately in the presence of both externall y-generated differential and common - mode noise. An example of differential -mode noise that can appear at the inputs of a current -sense amplifier is high -frequency ripple. High -frequency ripple – whether injected into the circuit inductively or capacitively - can produce a differential -mode voltage drop across the external current -shunt resistor (RSENSE). An example of externally - generated, common -mode noise is the high - frequency output ripple of a switching regulator that can result in common -mode noise injection into both inputs of a current-sense amplifier. Even though the load current signal bandwidth is DC, the input stage of any current -sense amplifier can rectify unwanted, out -of-band noise that can result in an apparent error voltage at its output. T his rectification of noise signals occurs because all amplifier input stages are constructed with transistors that can behave as high -frequency signal detectors in the same way pn -junction diodes were used as RF envelope detectors in early radio designs. A gainst common -mode injected noise, the amplifier’s internal common -mode rejection is usually sufficient. To counter the effects of externally -injected noise, it has always been good engineering practice to add external low-pass filters in series with the inputs of a current-sense amplifier. In the design of discrete current-sense amplifiers, resistors used in the external low -pass filters were incorporated into the circuit’s overall design so errors because of any input-bias current -generated offset voltag e errors and gain errors were compensated. With the advent of monolithic current -sense amplifiers, like the TS110 1, the addition of external low-pass filters in series with the current -sense amplifier’s inputs only introduces additional offset voltage and gain errors. To minimize or eliminate altogether the need for external low -pass filters and to maintain low input offset voltage and gain errors, the TS110 1 incorporates a 50 -kHz (typ), 2 nd-order differential low-pass filter as shown in the TS110 1’s Block Diagram. Output Filter Capacitor If the TS1101 is part of a signal acquisition system where its OUT terminal is connected to the input of an ADC with an internal, switched -capacitor track - and-hold circuit, the internal track -and-hold’s sampling capacitor can cause voltage droop at V OUT. A 22nF to 100nF good-quality ceramic capacitor from the OUT terminal to GND forms a low -pass filter with the TS1101’s R OUT and should be used to minimize voltage droop (holding V OUT constant during the sample interval. Us ing a capacitor on the OUT terminal will also reduce the TS1101’s small- signal bandwidth as well as band -limiting amplifier noise. PC Board Layout and Power-Supply Bypassing For optimal circuit performance, the TS1101 should be in very close proximity to the external current - sense resistor and the pcb tracks from RSENSE to the RS+ and the RS - input terminals of the TS1101 should be short and symmetric. Also recommended are a ground plane and surface mount resistors and capacitors. Figure 3: Making PCB Connections to RSENSE.

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+1 (408) 215 - 1220 ▪ www.touchstonesemi.com RTFDS PACKAGE OUTLINE DRAWING 6-Pin SOT23 Package Outline Drawing (N.B., Drawings are not to scale) Information furnished by Touchstone Semiconductor is believed to be accurate and reliable. However, Touchstone Semiconductor does not assume any responsibility for its use nor for any infringements of patents or other rights of third parties that may result f rom its use, and all information provided by Touchstone Semiconductor and its suppliers is provided on an AS IS basis, WITHOUT WARR ANTY OF ANY KIND. Touchstone Semiconductor reserves the right to change product specifications and product descriptions at any time without any advance notice. No license is granted by implication or otherwise under any patent or patent rights of Touchston e Semiconductor. Touchstone Semiconductor assumes no liability for applications assistance or customer product design. Customers are responsible for thei r products and applications using Touchstone Semiconductor components. To minimize the risk associated with customer products and applications, customers should provide adequate design and operating safeguards. Trademarks and registered trademarks are the property of t heir respective owners. 0° ~ 8° Note: Dimension are exclusive of mold flash and gate burr. 2. Dimension are exclusive of solder plating. 3. The foot length measuring is based on the gauge plane method. 4. Package is surface to be matte finish VDI 11~13. 5. Dimensions and tolerances are as per ANSI Y14.5M, 1982. 6. This part is compliant with EIAJ specification SC74A and JEDEC MO-178 AB spec. 7. Die is facing up for mold, Die is facing down for trim/form, ie. reverse trim/form. 8. All dimensions are in mm. 0.050(MIN) 0.15(MAX) 0.90 - 1.45 10° TYP. (2 Plcs) 10° TYP. (2 Plcs) 0.60 - 0.80 10° TYP. (2 Plcs) 0.09 – 0.127 1.50 – 1.75 0.25 Guage Plane 0.30 - 0.55 10° TYP. (2 Plcs) 0.50 -0.70 2.80 - 3.00 0.950 0.950 TYP. TYP. 2.60 - 3.00 1.50 - 1.75 0.300(MIN) 0.500(MAX)