austriamicrosystems AG is now ams AG The technical content of this austriamicrosystems datasheet is still valid. Contact information: Headquarters: ams AG Tobelbaderstrasse 30 8141 Unterpremstaetten, Austria Tel: +43 (0) 3136 500 0 e-Mail: [email protected] Please visit our website at www.ams.com Data Sheet AS8002 S o l a r P h o t o v o l t a i c I n v e r t e r M e a s u r em e n t I C w i t h F a s t O v e r C u r r e n t Detection The AS8002 is a highly accurate measurement IC that allows monitoring the generated energy with low cost shunt resistors or other sensors for the current and resistor dividers for the voltage. Programmable gain amplifiers to accommodate for different sensors Three multiplexed inputs to the 12-Bit ADC for secondary measurements that require high accuracy and fast sampling rates On chip temperature sensor connected to one of the inputs of the multiplexer On-chip voltage reference with small temperature coefficient (10ppm/K typ). This reference is available at the pin REF. am lc s on A te G nt st il This approach allows avoiding more expensive sensing devices while achieving the required accuracy for DC and AC measurements of current and voltage, as well as stability over the operating temperature range of the inverter. 12-Bit 100 kSPS ADCs for accurate voltage and current measurement al id Power inverters in solar photovoltaic systems are often connected directly to the electricity grid in order to inject the created energy into the mains and act as an electricity supplier. This energy must comply with certain regulations that set the standard in terms of quality and safety which requires of accurate measurements. 2 Key Features lv 1 General Description The 12-bit ADC samples the voltage and current and provides their instantaneous values through an SPI interface. Low power on chip oscillator The 12-bit ADC is preceded by low noise programmable gain amplifiers in order to accommodate different sensors. Internal registers for easy offset and gain compensation The ADC has three multiplexed inputs, offering one secondary channel in addition to the main voltage and current. The on-chip temperature sensor provides the inverter designer the option of temperature compensation for any of the measured parameters or functional blocks provided, over the full operating temperature range of the device. The on-chip voltage reference is connected to the ADC and to REF. An external crystal oscillator is not required as a high accuracy internal oscillator clock is available. SPI compatible interface Interrupt alerts (including Under Voltage Lock-Out and Over Temperature) Independent programmable over current interrupt 3 Applications The AS8002 is suitable for PV inverter grid monitoring, Wind inverter grid monitoring, Isolated voltage sensing, Uninterruptible Power supplies and Power conditioners. Te ch ni ca The independent over current interrupt detects a high current on the grid and allows the processor to open the switches without waiting for the ADC conversion. www.austriamicrosystems.com/AS8002 Revision 1.1 1 - 24 AS8002 Data Sheet - A p p l i c a t i o n s Curr IOP_VOP IOM_VOM DVDD REF AS8002 V1M V2P V2M 12-Bit ADC Volt V1P am lc s on A te G nt st il OSC REF lv AVDD al id Figure 1. AS8002 Block Diagram CAL SCSB CTRL SCLK UVLO I/F TEMP OV TEMP SDO XINT AVSS DVSS Te ch ni ca OVER CURR SDI www.austriamicrosystems.com/AS8002 Revision 1.1 2 - 24 AS8002 Data Sheet - C o n t e n t s Contents 1 2 Key Features............................................................................................................................................................................. 1 3 Applications............................................................................................................................................................................... 1 4 Pin Assignments ....................................................................................................................................................................... 4 4.1 Pin Descriptions.................................................................................................................................................................................... 4 al id 1 General Description .................................................................................................................................................................. 5 6 Electrical Characteristics........................................................................................................................................................... 6 6.1 Operating Conditions............................................................................................................................................................................ 6 6.2 Block Electrical Characteristics ............................................................................................................................................................ 6 7 Detailed Description.................................................................................................................................................................. 9 7.1 Operating Modes ................................................................................................................................................................................ 10 7.2 SPI Interface....................................................................................................................................................................................... 10 7.3 SPI Interface Data Transfer Protocol.................................................................................................................................................. 10 7.4 11 am lc s on A te G nt st il lv 5 Absolute Maximum Ratings ...................................................................................................................................................... SPI Hardware Connection .............................................................................................................................................................. 7.5 SPI Timing .......................................................................................................................................................................................... 12 7.6 13 Measurement Example ................................................................................................................................................................... 7.7 Measurement Control and Calibration ............................................................................................................................................ 14 7.8 Interrupts......................................................................................................................................................................................... 14 7.9 Register Map Table............................................................................................................................................................................. 15 7.10 Register Description ......................................................................................................................................................................... 16 8 Application Information ........................................................................................................................................................... 21 8.1 Application Hints................................................................................................................................................................................. 21 22 10 Ordering Information............................................................................................................................................................. 24 Te ch ni ca 9 Package Drawings and Markings ........................................................................................................................................... www.austriamicrosystems.com/AS8002 Revision 1.1 3 - 24 AS8002 Data Sheet - P i n A s s i g n m e n t s 4 Pin Assignments al id SCL SCSB DVDD AVDD Figure 2. Pin Assignments (Top View) SDI IOP_VOP AS8002 QFN16 4x4x0.9 V1P SDO XINT DVSS AVSS REF V2M V2P am lc s on A te G nt st il V1M lv IOM_VOM 4.1 Pin Descriptions Table 1. Pin Descriptions Pin Name IOP_VOP IOM_VOM V1P V1M V2P REF Analog pin Analog Input Channel 0. Positive input of the differential analog input. 2 Analog pin Analog Input Channel 0. Negative input of the differential analog input. 3 Analog pin Analog Input Channel 1. Positive input of the differential analog input. 4 Analog pin Analog Input Channel 1. Negative input of the differential analog input. 5 Analog pin Analog Input Channel 2. Positive input of the differential analog input. 6 Analog pin Analog Input Channel 2. Negative input of the differential analog input. 7 Analog pin Reference Positive Input Voltage. 8 Supply pin Ground reference for the analog circuitry. Supply pin Ground reference for the digital circuitry. ch XINT 1 ni AVSS DVSS Pin Type ca V2M Pin Number 9 10 Description Digital input/output Interrupt pin, active low pin 11 Digital output pin Serial peripheral interface (SPI): Serial Data Output SDI 12 Digital input pin Serial peripheral interface (SPI): Serial Data input SCLK 13 Digital input pin Serial peripheral interface (SPI): Serial Clock SCSB 14 Digital input pin Serial peripheral interface (SPI): Serial Chip Select (active low) DVDD 15 Supply pin Digital positive supply AVDD 16 Supply pin Analog positive supply AVSS PAD Supply pin Ground reference for the analog circuitry. Te SDO Note: Pin number assignment is likely to change. www.austriamicrosystems.com/AS8002 Revision 1.1 4 - 24 AS8002 Data Sheet - A b s o l u t e M a x i m u m R a t i n g s 5 Absolute Maximum Ratings Stresses beyond those listed in Table 2 may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in Block Electrical Characteristics on page 6 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Parameter Min Max Units Comments DC supply voltage (VDD) -0.3 +5.0 V AVDD, DVDD Input pin voltage (VIN) -0.3 VDD+0.3 V Electrostatic discharge (ESD) -1000 1000 V Storage temperature (Tstrg) -55 125 ºC al id Table 2. Absolute Maximum Ratings Norm: MIL 883 E method 3015 lv The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/ JEDEC J-STD-020 “Moisture/Reflow Sensitivity Classification for Non-Hermetic Solid State Surface Mount Devices”. am lc s on A te G nt st il Lead temperature profile (Tbody) 5 85 % Te ch ni ca Humidity non-condensing www.austriamicrosystems.com/AS8002 Revision 1.1 5 - 24 AS8002 Data Sheet - E l e c t r i c a l C h a r a c t e r i s t i c s 6 Electrical Characteristics 6.1 Operating Conditions Table 3. Operating Conditions Conditions Min Typ Max Units 3.3 3.6 V 0 V 0.1 V 3.6 V 0 V AVDD Positive analog supply voltage 3.0 AVSS Negative analog supply voltage 0 A-D Difference of supplies DVDD Positive digital supply voltage 3.0 DVSS Negative digital supply voltage 0 TAMB Ambient temperature -40 ISUPP Supply current -0.1 3.3 25 125 ºC 5 mA am lc s on A te G nt st il AVDD – DVDD AVSS – DVSS al id Parameter lv Symbol 6.2 Block Electrical Characteristics AVDD=3.0V to 3.6V, TAMB= -40 to +125ºC. Typical values at TAMB= +25ºC and AVDD=3.3V (unless otherwise specified). Table 4. Block Electrical Characteristics Symbol Parameter ADC DC Accuracy Conditions Min Typ Max Units 12 Bits -0.99 +0.99 LSB -0.99 +0.99 LSB ±4 LSB Resolution RES INL Integral Nonlinearity DNL Differential Nonlinearity OFS Offset Error ±0.6 OFSM Offset Error Match ±0.1 GAIN Gain Error Guaranteed No Missed Codes to 12 Bits ±4 Gain Error Match GAINM LSB LSB ±0.1 LSB 71 dB 72 dB -78 dB 84 dB fIN = 40kHz -79 dB at 3dB 35 at 0.1dB 3.6 ADC Dynamic Specifications fIN=10 kHz Sine Wave Input Signal to Noise = Distortion Ratio SNR Signal-to-Noise Ratio THD Total Harmonic Distortion SFDR Spurious-Free Dynamic Range CCISOL Channel-to-Channel Isolation Full Power Bandwidth ch FLBW ni FPBW ca SINAD fIN = 10kHz MHz ADC Analog Inputs of the Analog-to-Digital Converter Differential Input Voltage Ranges -VREF VREF V VCMIN Input Common Mode Voltage VREF/2 VDDVREF/2 V AILEAK DC Leakage Current -1 +1 µA Te VX+ – VX- AIIZT AIIZH Input Capacitance Track mode TBD pF Hold mode TBD pF ADC Conversion Rate tCONV Conversion Time www.austriamicrosystems.com/AS8002 Running from the internal oscillator Revision 1.1 10 µs 6 - 24 AS8002 Data Sheet - E l e c t r i c a l C h a r a c t e r i s t i c s Table 4. Block Electrical Characteristics Symbol Parameter Conditions Min Typ tACQUISITION Track-and-Hold Acquisition Time TPUT Throughput Rate APERTURE Aperture Delay 4 ns JITTER Aperture Jitter 50 ps RFTC Internal Reference Drift TBD µs KSPS Typical accuracy ±TBD% 2.5 10 Programmable Gain Amplifiers Programmable | VV0_I0 | Input level 0 Differential, with gain of 64 AMPGAIN1 Gain channel 1 Programmable | VV1 | Input level 1 Differential, with gain of 6 2 2 ppm/ºC 64 V/V 14 20 mVP c 8 V/V 150 212 mVP lv Gain channel 0 V am lc s on A te G nt st il AMPGAIN0 al id Range Units 100 Reference Output RFRNG Max AMPOFFED Offset error drift -20 20 µV AMPGAINED Gain error drift -0.1 0.1 % AMPTHD Total harmonic distortion Temperature Sensor TBD TEMPAERR Absolute Error (trimmed) -5 +5 ºC TEMPRERR Relative Error (trimmed) -3 +3 ºC TEMPRNG Temperature Range -40 85 ºC TEMPRES Resolution 0.75 ºC/LSB Frequency 10 MHz Internal Oscillator OSCFREQ Relative Error OSCERROR Over Current OVCURRDE LAY OVCURRER ROR Relative Error UVLOHYST % 2 µs -20 +20 For threshold higher than 50mV -10 +10 % High Threshold 2.85 V Hysteresis 0.1 V VIH Input High Voltage VIL Input Low Voltage IIN Input Current CIN Input Capacitance Te +10 For threshold lower than 50mV ch Digital Inputs From chip input to output ni Under Voltage Lock Out UVLOHI ca Reaction Time -10 0.7xDVD D VIN=0V or DVDD V -1 0.3xDVD D V +1 µA 15 pF Digital Outputs VOH Output High Voltage ISOURCE = 200 µA; DVDD = 3 to 3.6V VOL Output Low Voltage ISINK = 200 µA www.austriamicrosystems.com/AS8002 Revision 1.1 DVDD 0.2 V 0.4 V 7 - 24 AS8002 Data Sheet - E l e c t r i c a l C h a r a c t e r i s t i c s Table 4. Block Electrical Characteristics Symbol Parameter Coding Output Coding Conditions Min Typ Max Units 3.6 V Two’s complem ent Positive Supply Voltage VDD 3 AVDD= 3V, fSAMPLE = 100ksps Input amplifier OFF AVDD = 3V, fSAMPLE = 100ksps Input amplifier ON IDD µA 5 mA 1 µA Te ch ni ca am lc s on A te G nt st il lv Full shutdown mode (Off mode) 650 al id Power Requirements www.austriamicrosystems.com/AS8002 Revision 1.1 8 - 24 AS8002 Data Sheet - D e t a i l e d D e s c r i p t i o n 7 Detailed Description Figure 3 presents a typical application schematic for the AS8002 used for voltage and current measurement of a device connected to the grid such a solar inverter or microinverter. al id The external circuitry comprises the power supply unit that is connected to the grid signal and that generates a stable DC voltage which is the supply of the AS8002 and the digital isolation. Both current and voltage are scaled down and filtered prior to be sensed by the AS8002. In the case of the voltage, a resistor divider is enough to scale down the voltage. In the case of the current, a low ohmic shunt resistor should be used. The value of this shunt resistor should be calculated in order not to saturate the inputs of the AS8002 but to provide a good signal to noise ratio. It is also important to minimize the value of the shunt resistor to lower the losses and increase the overall efficiency. lv Unlike commonly used sensing methods, the AS8002 is connected to the same potential level as the grid, which allows using a low cost shunt resistor as the sensing device. The isolation is achieved by means of a digital isolator which should be able to handle a data rate of up to 2Mbps. This sensing solution has several advantages compared to other common solutions, like the stability over temperature, accuracy of the measurements and allowed bandwidth. All these lead to an accurate control of the DC-AC converter with low DC injection currents. Te ch ni ca am lc s on A te G nt st il Figure 3. Typical Application Circuit www.austriamicrosystems.com/AS8002 Revision 1.1 9 - 24 AS8002 Data Sheet - D e t a i l e d D e s c r i p t i o n 7.1 Operating Modes When the supply voltage is below the threshold VPOR, the AS8002 is in Reset mode. Once the supply voltage is higher than VPOR, the AS8002 goes into Off mode during its initialization time tINIT. In this mode, the current consumption is reduced and only the Control register can be read or written. Once the register bit chip_en has been set to 1, the chip goes into On mode and can be normally used after tWAKEUP. The chip can go immediately back to Off mode by setting chip_en to 0. Table 5. Characteristics Description Min VPOR POR threshold voltage 2.6 tINIT Initialization time 3 tWAKEUP Wake up time 300 Unit V ms µs lv 7.2 SPI Interface Max al id Parameter The 16-bit SPI interface enables read / write access to the register blocks and is compatible to a standard micro controller interface, using SPI Mode 3 (SCLK initial state = high, data latched with rising edge of SCLK). am lc s on A te G nt st il The SPI module is active as soon as pin SCSB is pulled low. The AS8002 is then ready to read the 8-bit SPI address on the SDI input with every rising edge of SCLK and writes on its SDO output with the falling edge of SCLK. After 16 clock cycles SCSB has to be set back to high status in order to reset the interface for the next read/write cycle. th The address is split into an upper 7 bit address (addr[0…6]) and a lower 8 bit (R/W) containing the read/write information. Writing data to the AS8002 is established by setting the R/W bit to 0. The 8 bits following this bit on SDI contain the data to be written into the address specified in the first 8 bits. Reading data is established by setting the R/W bit to 1. The 8 bits following this bit on SDO contain the data from the address specified in the first 8 bits on SDI. Figure 4. Write Mode SCSB SCLK ca 7.3 SPI Interface Data Transfer Protocol addr[6:0] 6 5 4 3 ni SDI 2 1 R/W 0 data[7:0] 7 6 5 7 6 5 4 3 2 2 1 0 1 0 4 3 2 1 0 Te ch SDO 5 3 read_meas_LSB[7:0] read_meas_MSB[7:0] 6 4 www.austriamicrosystems.com/AS8002 Revision 1.1 10 - 24 AS8002 Data Sheet - D e t a i l e d D e s c r i p t i o n Figure 5. Read Mode SCLK addr[6:0] 5 4 6 5 3 2 1 0 data_addr[7:0] read_meas_MSB[7:0] 3 2 1 0 7 6 5 4 3 2 1 0 am lc s on A te G nt st il SDO 4 lv 6 SDI R/W al id SCSB The interface of the AS8002 corresponds to a 4-wire SPI where each data transfer is composed of 16 bits. Each 16-bit transfer of the SDI is divided into a 7-bit address word indicating the target register, one R/W bit indicating the operation to be done and a 8-bit word data indicating the data to be written. The data transferred in SDO is also composed of 16 bits. These can be divided into the 8 MSBs which correspond to the 8 MSBs of the last conversion run by the ADC plus 8 LSBs which clock out the data that has been requested by the SDI in that same cycle. This allows for a given read register to be addressed and read in the same 16-bit transfer. 7.4 SPI Hardware Connection Figure 6 shows a basic interconnection diagram of an AS8002 device with a host controller. Data transmission is enabled with signal SCSB (SS/ ), the serial clock is applied at pin SCLK (SCK). Data is shifted into the AS8002 via signal SDI (MOSI) and read from the AS8002 via signal SDO (MISO). SDI MISO SDO SCK SCLK SS/ SCSB UC Te ch ni MOSI AS8002 ca Figure 6. AS8002 and the Controller www.austriamicrosystems.com/AS8002 Revision 1.1 11 - 24 AS8002 Data Sheet - D e t a i l e d D e s c r i p t i o n 7.5 SPI Timing al id Figure 7. Timing Diagram tXSSH SCSB (Input) tsclk tsclkL tsclkH tH lv tL SCLK (Input) SDO (Output) tOZ am lc s on A te G nt st il tSDO data[15] data[14] data[0] tOZ tSDI SDI (Input) data[15] data[14] data[0] Parameter tL tSCLKL tSCLKH Description Min Max Unit Time between SCSB falling edge and SCK rising edge 350 ns Serial clock period 100 ns Low period of serial clock 50 ns ni tSCLK ca Table 6. Timing Characteristics 50 ns tH tSCK / 2 ns tXSSH High time of SCSB between two transmissions 350 ns tSDI Data input valid to rising clock edge 20 ns tSDO SCLK falling edge to data output valid Te ch High period of serial clock Time between last falling edge of SCK and rising edge of SCSB 20 ns Note: The data on SDO initially reflects the data corresponding to the previous command on SDI. Hence, in write mode, the full 16-bit data of a measurement can be read. www.austriamicrosystems.com/AS8002 Revision 1.1 12 - 24 AS8002 Data Sheet - D e t a i l e d D e s c r i p t i o n 7.6 Measurement Example The following example shows a simple way to alternately read the voltage and current values: Bits [b2:b0] in Addr 03h control the ADC input multiplexer: Addr Default Input Multiplexer 03h 00h Content b7 b6 b5 b4 b3 b2 b1 b0 mux_sel[2:0] 0: Current channel PGA output 1: Voltage channel PGA output al id Name adc_en am lc s on A te G nt st il lv 1. Select the Current channel input (IOM, IOP) : 0610h - Set the Address [A6:A0] to 03h, - Set the R/W bit to 0 (write mode) and the data to 10h (adc_en = 1, mux_sel = 0) - In parallel to writing the 16-bit data on SDI, a set of 16-bit data can be read on SDO, which contains the data from the second to last command. 2. Select the Voltage channel input (V1M, V1P) : 0611h - Set the Address [A6:A0] to 03h, - Set the R/W bit to 0 (write mode) and the data to 11h (adc_en = 1, mux_sel = 1) - In parallel to writing the 16-bit data on SDI, a set of 16-bit data can be read on SDO, which contains the data from the second to last command. 3. Change the input multiplexer back to Current channel input (IOM, IOP) : 0610h - Repeat the sequence 1 above: addr = 03h, data = 10h, - The 16-bit current input data from the second to last invoked command (1 above) can be read on SDO. 4. Loop sequences 2 and 3 Note: In sequence 2, the 16-bit voltage input data from the second to last command can be read on SDO. Figure 8. Measurement Diagram 1) MSB 2) 0610h LSB MSB 0611h 3) LSB MSB 0610h 4)=2) LSB MSB 0611h set Mux to Current measurement set Mux to Voltage measurement set Mux to Current measurement set Mux to Voltage measurement SDO data from previous command data from previous command read Current input value read Voltage input value ni ca SDI LSB ch MSB LSB Transmission 2 MSB LSB Transmission 3 MSB LSB Transmission 4 Te Transmission 1 MSB LSB Note: The 16-bit input data from the voltage and current measurements contain the ADC data in the lower 12 bits and two status bits in the upper 4 bits (see Register Map Table on page 15). www.austriamicrosystems.com/AS8002 Revision 1.1 13 - 24 AS8002 Data Sheet - D e t a i l e d D e s c r i p t i o n Table 7. Current and Voltage Measurements Content Name b14 b13 b12 b11:b0 Current Measurement 0 warning_detected interrupt_detected X curr_meas Voltage Measurement 0 warning_detected interrupt_detected X volt_meas al id b15 7.7 Measurement Control and Calibration The conversion starts on SCSB falling edge when adc_en is a 1. The value of the result of the conversion can be read at the next SPI write command 10µs later. channel measured channel read am lc s on A te G nt st il SCSB lv Figure 9. ADC Burst Mode Not updated channel_1 Not updated channel_2 channel_3 channel_1 channel_2 Read_meas will be transferred to the Current, Voltage or Auxiliary measurement upon mux_sel[2:0] value – curr_meas, volt_meas or aux_meas. Calibration is done according to the formulas: For voltage channel: (EQ 1) read_meas = adc_meas * (1024 + pga_volt_gain_cal) / 1024 (EQ 2) ni For auxiliary channel: read_meas = adc_meas * (1024 + pga_curr_gain_cal) / 1024 ca For current channel: read_meas = adc_meas * (1024 + aux_gain_cal) / 1024 (EQ 3) ch Note: The Raw ADC results are also available in the registers and are called adc_meas[11:0] 7.8 Interrupts When an over current, an under voltage or an over temperature occurs the bit warning_detected is set to 1. Te The interrupt state is present on interrupt_detected and on the pin XINT. The statuses are available in the register Interrupt Status. It contains the bits over_currrent_int_en, under_voltage_int_en, over_temp_int_en. The generation of the interrupt can be enabled or disabled in the register “Interrupt Enable”. It contains the bits over_currrent_int_i, under_voltage_int_i, over_temp_int_i. Values of the register Interrupt Status are kept until this register is read. www.austriamicrosystems.com/AS8002 Revision 1.1 14 - 24 AS8002 Data Sheet - D e t a i l e d D e s c r i p t i o n 7.9 Register Map Table Table 8. Register Map Content Name Addr Default Control 01h 00h PGA Gain 02h 00h Input Multiplexer 03h 00h adc_en Over Temperature Threshold 04h FFh over_temp_thres[7:0] Interrupt Enable 05h 00h Over Current Range 06h FFh Current Measurement MSB 10h 00h Current Measurement LSB 11h 00h Voltage Measurement MSB 12h 00h Voltage Measurement LSB 13h 00h Auxiliary Measurement MSB 14h 00h Auxiliary Measurement MSB 15h 00h aux_meas[7:0] Temperature Measurement 16h 00h temp[7:0] Interrupt Status 17h 00h b5 b4 b3 b2 b1 b0 over_ current_ch annel over_ current_ en adc_ref_ en pga_ volt_en pga_ curr_en temp_ sensor_ en chip_en pga_volt_gain[1:0] pga_curr_gain[4:0] al id b6 mux_sel[2:0] lv b7 over_ current_int _en am lc s on A te G nt st il over_current_range[7:0] under_ voltage_ int_en 0 warning_ detected interrupt_ detected X over_ temp_int_ en curr_meas[11:8] curr_meas[7:0] 0 warning_ detected interrupt_ detected X volt_meas[11:8] volt_meas[7:0] ca 0 warning_ detected interrupt_ detected X aux_meas[11:8] over_ current_i under_ voltage_i over_ temp_i 18h 02h 0 0 0 0 0 0 1 0 19h 5Xh 0 1 0 1 X X X X 1Ah 00h 0 warning_ detected interrupt_ detected X Raw ADC Results LSB 1Bh 00h adc_meas[7:0] PGA Current Gain Calibration 3Ah 00h pga_curr_gain_cal[7:0] PGA Voltage Gain Calibration 3Bh 00h pga_volt_gain_cal[7:0] Auxiliary Channel Gain Calibration 3Ch 00h aux_gain_cal[7:0] ASIC ID 1 ASIC ID 2 Te ch ni Raw ADC Results MSB adc_meas[11:8] Note: Highlighted registers are Read only registers (bits). www.austriamicrosystems.com/AS8002 Revision 1.1 15 - 24 AS8002 Data Sheet - D e t a i l e d D e s c r i p t i o n 7.10 Register Description Table 9. 01h Control Register Address: 01h Controls the power on and off of the internal blocks Bit Name Default Access 0 chip_en 0h R/W 0: Chip in complete power off 1: Chip on 1 temp_sensor_en 0h R/W 0: Temperature sensor disabled 1: Temperature sensor enabled 2 pga_curr_en 0h R/W 0: Current channel PGA disabled 1: Current channel PGA enabled 3 pga_volt_en 0h R/W 0: Voltage channel PGA disabled 1: Voltage channel PGA enabled 4 adcref_en 0h R/W 0: Internal ADC reference voltage off 1: Internal ADC reference voltage on Note: This bit must be set to allow ADC measurements. 5 over_current_en 0h R/W 0: Over current detector disabled 1: Over current detector enabled 6 over_current_channel 0h R/W 0: Over current detector connected to inputs IOP_VOP and IOM_VOM 1: Over current detector connected to inputs V2P and V2M Address: 02h PGA Gain Register Controls the gain of the current and voltage channel PGAs Bit Name Default Access 4:0 pga_curr_gain 00h R/W 7:6 pga_volt_gain 0h R/W Address: 03h Default ni Bit Name 4 Gain for current channel is given by the formula: 2*pga_curr_gain+2 (EQ 4) Gain for voltage channel is given by the formula: 2*pga_volt_gain+2 (EQ 5) Input Multiplexer Register Controls the ADC and select the channel to be converted Access Description mux_sel 00h R/W adc_en 0h R/W Enable the ADC conversion that will start on the next SCSB falling edge Te 2:0 Description Select the input to be converted: 0: Current channel PGA output 1: Voltage channel PGA output 2: V2P and V2M 3: AVDD and AVSS 4: IOP_VOP and IOM_VOM 5: V1P and V1M 6: Reserved 7: Reserved ch Bit ca Bit Table 11. 03h lv am lc s on A te G nt st il Table 10. 02h Description al id Bit www.austriamicrosystems.com/AS8002 Revision 1.1 16 - 24 AS8002 Data Sheet - D e t a i l e d D e s c r i p t i o n Table 12. 04h Over Temperature Threshold Register Address: 04h Set the over temperature threshold value Bit Name Default Access 7:0 over_temp_thres FFh R/W Description Over temperature detection is triggered when temp value is higher than over_temp_thres Table 13. 05h Interrupt Enable Register Address: 05h Separately enables the interrupts Bit Name Default Access 0 over_temp_int_en 0h R/W 0: Interrupt due to over temperature is disabled 1: Interrupt due to over temperature is enabled 1 under_voltage_int_en 0h R/W 0: Interrupt due to under voltage is disabled 1: Interrupt due to under voltage is enabled 2 over_current_int_en 0h R/W 0: Interrupt due to over current is disabled 1: Interrupt due to over current is enabled Address: 06h am lc s on A te G nt st il Table 14. 06h Description lv Bit al id Bit Over Current Range Register Set the over current comparators absolute threshold voltage Bit Bit Name Default Access 7:0 over_current_range FFh R/W Description The threshold voltage is given by the formula: over_current_range*1m (EQ 6) Where: over_current_range should be higher than 10h Table 15. 10h Address: 10h Current Measurement MSB Register Gives measured value of current (MSB) and status of warnings and interrupts Bit Name 3:0 curr_meas[11:8] ni interrupt detected ch 5 warning detected 0h 0h 0h Access Description R MSB of current channel measurement, value is given as 2’s complement number by the formula: I=curr_meas*1.22m / (Rshunt*curr_gain) R Same value as XINT (complemented) 0: No interrupt detected 1: Interrupt is detected R Over temperature, under voltage or over current detected 0: No warning detected 1: Warning detected (EQ 7) Te 6 Default ca Bit www.austriamicrosystems.com/AS8002 Revision 1.1 17 - 24 AS8002 Data Sheet - D e t a i l e d D e s c r i p t i o n Table 16. 11h Current Measurement LSB Register Address: 11h Gives measured value of current (LSB) Bit Name Default Access 7:0 curr_meas[7:0] 0h R Description LSB of current channel measurement, value is given as 2’s complement number by the formula: I=curr_meas*1.22m / (Rshunt*curr_gain) Table 17. 12h Voltage Measurement MSB Register Address: 12h (EQ 8) al id Bit lv Gives measured value of voltage (MSB) and status of warnings and interrupts Bit Bit Name Default Access Description 3:0 volt_meas[11:8] 0h R MSB of voltage channel measurement, value is given as 2’s complement number by the formula: am lc s on A te G nt st il volt_meas*1.22m / volt_gain 5 interrupt detected 0h R Same value as XINT (complemented) 0: No interrupt detected 1: Interrupt is detected 6 warning detected 0h R Over temperature, under voltage or over voltage detected 0: No warning detected 1: Warning detected Table 18. 13h Address: 13h (EQ 9) Voltage Measurement LSB Register Gives measured value of voltage (LSB) Bit Bit Name Default Access Description 7:0 volt_meas[7:0] 0h R LSB of voltage channel measurement, value is given as 2’s complement number by the formula: Table 19. 14h Address: 14h Default Access Description aux_meas[11:8] 0h R MSB of auxiliary channel measurement, value is given as 2’s complement number by the formula: interrupt detected Te 5 6 Auxiliary Measurement MSB Register Bit Name ch 3:0 (EQ 10) Gives measured value of auxiliary channel (MSB) and status of warnings and interrupts ni Bit ca volt_meas*1.22m / volt_gain warning detected www.austriamicrosystems.com/AS8002 aux_meas*1.22m 0h R Same value as XINT (complemented) 0: No interrupt detected 1: Interrupt is detected 0h R Over temperature, under auxiliary or over auxiliary detected 0: No warning detected 1: Warning detected Revision 1.1 (EQ 11) 18 - 24 AS8002 Data Sheet - D e t a i l e d D e s c r i p t i o n Table 20. 15h Auxiliary Measurement LSB Register Address: 15h Gives measured value of auxiliary channel (LSB) Bit Bit Name Default Access Description 7:0 aux_meas[7:0] 0h R LSB of auxiliary channel measurement, value is given as 2’s complement number by the formula: Table 21. 16h Temperature Measurement Register Address: 16h Bit Name Default Access 7:0 temp 0h R Table 22. 17h Address: 17h Bit Description Temperature value (in °C) is given by the formula: 92+temp*3/4 Interrupt Status Register Gives status of each interrupt source Bit Name Default Access Description 0 over_temp_i 0h R 0: over temperature not detected 1: over temperature detected 1 under_voltage_i 0h R 0: under voltage not detected 1: under voltage detected 2 over_current_i 0h R 0: over current not detected 1: over current detected Table 23. 18h Address: 18h ASIC ID 1 Register Provides Chip identification Bit Name 7:0 asic_id R Description Chip indentification ASIC ID 2 Register Provides chip version number Default Access asic_version 5Xh R Description 50h: Chip version 0 51h: Chip version 1 Te 7:0 Access Bit Name ch Bit 02h ni Address: 19h Default ca Bit Table 24. 19h (EQ 13) am lc s on A te G nt st il Bit lv Gives measured value of temperature (EQ 12) al id aux_meas*1.22m www.austriamicrosystems.com/AS8002 Revision 1.1 19 - 24 AS8002 Data Sheet - D e t a i l e d D e s c r i p t i o n Table 25. 1Ah Raw ADC Results MSB Register Address: 1Ah Gives measured value of the ADC (MSB) and status of warnings and interrupts Bit Name Default Access 3:0 adc_meas[11:8] 0h R Description MSB of raw ADC measurement, value is given as 2’s complement number by the formula: adc_meas*1.22m interrupt detected 0h R Same value as XINT (complemented) 0: No interrupt detected 1: Interrupt is detected 6 warning detected 0h R Over temperature, under voltage or over current detected 0: No warning detected 1: Warning detected lv 5 Bit am lc s on A te G nt st il Table 26. 1Bh Address: 1Bh Raw ADC Results LSB Register Gives measured value of raw ADC (LSB) Bit Name 7:0 Default adc_meas[7:0] 0h Access Description R LSB of raw ADC measurement, value is given as 2’s complement number by the formula: adc_meas*1.22m Table 27. 3Ah Address: 3Ah Set value of correction coefficient for current measurement Bit Name Default Access 7:0 pga_curr_gain_cal 00h R/W Description Correct the measured current value multiplying it by the following factor, where pga_curr_gain_cal is a number defined as 2’s complement: Set value of correction coefficient for voltage measurement Default Access pga_volt_gain_cal 00h R/W Description Correct the measured voltage value multiplying it by the following factor, where pga_volt_gain_cal is a number defined as 2’s complement: (1024 + pga_volt_gain_cal) / 1024 ch 7:0 (EQ 16) PGA Voltage Gain Calibration Register Bit Name ni Bit ca (1024 + pga_curr_gain_cal) / 1024 Address: 3Bh (EQ 15) PGA Current Gain Calibration Register Bit Table 28. 3Bh (EQ 14) al id Bit (EQ 17) Table 29. 3Ch Auxiliary Channel Gain Calibration Register Te Address: 3Ch Bit 7:0 Bit Name aux_gain_cal Set value of correction coefficient for auxiliary measurement Default 00h Access R/W Description Correct the measured value of the auxiliary channel multiplying it by the following factor, where aux_gain_cal is a number defined as 2’s complement: (1024 + aux_gain_cal) / 1024 www.austriamicrosystems.com/AS8002 Revision 1.1 (EQ 18) 20 - 24 AS8002 Data Sheet - A p p l i c a t i o n I n f o r m a t i o n 8 Application Information Table 30 provides examples of Gain selection of Channel 1 for different shunt resistors and maximum RMS currents. Table 30. Gain Selection Sensing RMS Current (A) Recommended Linear Gain for Channel 1 for ADC to work in 80% of dynamic range 7.5 mΩ 1.5 Gain1 = 64 10 mΩ 1.5 Gain1 = 48 5 mΩ 3 Gain1 = 48 7.5 mΩ 3 Gain1 = 32 10 mΩ 3 Gain1 = 24 5 mΩ 6 7.5 mΩ 6 10 mΩ 6 lv al id Shunt Resistor Value Gain1 = 24 Gain1 = 16 am lc s on A te G nt st il Gain1 = 12 8.1 Application Hints Grounding and Layout. The analog and digital supplies of the AS8002 (AVDD, DVDD, AVSS, DVSS) are independent and separately pinned out to minimize coupling between the analog and digital sections of the device. The printed circuit board (PCB) that houses the AS8002 should be designed such that the analog and digital sections are separated and confined to certain areas on the board. This design facilitates the use of ground planes that can be easily separated. To provide optimum shielding for ground planes, a minimum etch technique is generally best. All VSS pins of the AS8002 should be sunk in the ground plane. Digital and analog ground planes should be joined in only one spot. If the AS8002 is in a system where multiple devices require an AVSS and DVSS connection, this connection should still be made at one point only; a star ground point that should be established as close as possible to the ground pins on the AS8002. Avoid running digital lines under the device as this couples noise into the chip. However, the analog ground plane should be allowed to run under the AS8002 to avoid noise coupling. The power supply lines to the AS8002 should use as large trace width as possible to provide low impedance paths and reduce the effects of glitches on the power supply line. Likewise, the positive supply pins AVDD and DVDD should be connected only at one common star point close the output of the power supply. For best performance of the analog blocks of the AS8002, it is important to have a clean, noise-free supply voltage at AVDD. ca To avoid radiating noise to other sections of the board, fast switching signals, such as clocks, should be shielded with digital ground, and clock signals should never run near the analog inputs. Avoid crossover of digital and analog signals. To reduce the effects of feedthrough within the board, traces on opposite sides of the board should run at right angles to each other. A microstrip technique is the best method but is not always possible with a double sided board. In this technique, the component side of the board is dedicated to ground planes, while signals are placed on the opposite side. Te ch ni Good decoupling is also important. All analog supplies should be decoupled with 10µF ceramic capacitors in parallel with 0.1µF capacitors to GND. Refer to Typical Application Circuit (page 9). To achieve the best results from these decoupling components, they must be placed as close as possible to the device The 0.1µF capacitors should have low effective series resistance (ESR) and low effective series inductance (ESI), such as common ceramic types or surface-mount types. These low ESR and ESI capacitors provide a low impedance path to ground at high frequencies to handle transient currents due to internal logic switching. www.austriamicrosystems.com/AS8002 Revision 1.1 21 - 24 AS8002 Data Sheet - P a c k a g e D r a w i n g s a n d M a r k i n g s 9 Package Drawings and Markings The device is available in a 16-pin QFN (4x4x0.9mm) package. 5 6 7 8 9 lv 4 al id Figure 10. 16-pin QFN (4x4x0.9mm) Package 3 10 11 am lc s on A te G nt st il 2 #1 12 Typ 0.85 0.203 REF 0.30 4.00 BSC 4.00 BSC 2.40 2.40 ni Min 0.75 0.25 ch Symbol A A1 b D E D2 E2 ca 16 0.35 2.50 2.50 Symbol e L L1 P aaa ccc Min 0.40 14 13 Typ 0.65 BSC 0.50 Max 0.60 0.10 45º BSC 0.15 0.10 Te 2.30 2.30 Max 0.95 15 Notes: 1. Dimensioning and tolerancing conform to ASME Y14.5M-1994. 2. All dimensions are in millimeters, angles are in degrees. 3. Dimension b applies to metallized terminal and is measured between 0.25 and 0.30mm from terminal tip. Dimension L1 represents terminal full back from package edge up to 0.1mm is acceptable. 4. Coplanarity applies to the exposed heat slug as well as the terminal. 5. Radius on terminal is optional. www.austriamicrosystems.com/AS8002 Revision 1.1 22 - 24 AS8002 Data Sheet - R e v i s i o n H i s t o r y Revision History Revision Date Owner Description 1.0 14 May, 2010 jja Initial revision 25 Aug, 2010 spo Te ch ni ca am lc s on A te G nt st il lv Note: Typos may not be explicitly mentioned under revision history. al id 1.1 Updated the following in Register Map (page 15): 1) Register bit b4 at address 01 (previously under_voltage_en) is now adc_ref_en 2) ASIC ID 2 register value is now 5Xh www.austriamicrosystems.com/AS8002 Revision 1.1 23 - 24 AS8002 Data Sheet - O r d e r i n g I n f o r m a t i o n 10 Ordering Information The devices are available as the standard products shown in Table 31. Table 31. Ordering Information Description Delivery Form Package AS8002 AQFP Temperature: -40ºC to 125ºC Tape & Reel in Dry Pack; 6000 pieces / reel 16-pin QFN (4x4x0.9mm) al id Ordering Code Note: All products are RoHS compliant and Pb-free. Buy our products or get free samples online at ICdirect: http://www.austriamicrosystems.com/ICdirect lv For further information and requests, please contact us mailto:[email protected] or find your local distributor at http://www.austriamicrosystems.com/distributor Copyrights am lc s on A te G nt st il Copyright © 1997-2010, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. All products and companies mentioned are trademarks or registered trademarks of their respective companies. Disclaimer Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. austriamicrosystems AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by austriamicrosystems AG for each application. For shipments of less than 100 parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location. ni ca The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems AG rendering of technical or other services. ch Contact Information Headquarters Te austriamicrosystems AG Tobelbaderstrasse 30 A-8141 Unterpremstaetten, Austria Tel: +43 (0) 3136 500 0 Fax: +43 (0) 3136 525 01 For Sales Offices, Distributors and Representatives, please visit: http://www.austriamicrosystems.com/contact www.austriamicrosystems.com/AS8002 Revision 1.1 24 - 24