Datasheet

ManualsBrandsANALOG DEVICES ManualsPMICsADT7411ARQZ

SPI

-/I

-Compatible, 10-Bit Digital

Temperature Sensor and 8-Channel ADC

ADT7411

Rev. B

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FEATURES

10-bit temperature-to-digital converter

10-bit 8-channel ADC

DC input bandwidth

Input range: 0 V to 2.25 V and 0 V to V

Temperature range: −40°C to +120°C

Temperature sensor accuracy of ±0.5°C

Supply range: 2.7 V to 5.5 V

Power-down current : <10 μA

Internal 2.25 V

REF

option

Double-buffered input logic

C, SPI, QSPI™, MICROWIRE™, and DSP compatible

4-wire serial interface

SMBus packet error checking (PEC) compatible

16-lead QSOP

APPLICATIONS

Portable battery-powered instruments

PCs

Smart battery chargers

Telecommunications systems electronic test equipment

Domestic appliances

Process controls

PIN CONFIGURATION

NC = NO CONNECT

AIN5

D+/AIN1

GND

AIN6

AIN8

AIN4

SCL/SCLK

INT/INT

D–/AIN2 AIN3

DOUT/ADD

SDA/DIN

AIN7

TOP VIEW

(Not to Scale)

ADT7411

02882-005

Figure 1.

GENERAL DESCRIPTION

The ADT7411

combines a 10-bit temperature-to-digital

converter and a 10-bit 8-channel ADC in a 16-lead QSOP. This

includes a band gap temperature sensor and a 10-bit ADC to

monitor and digitize the temperature reading to a resolution of

0.25°C. The ADT7411 operates from a single 2.7 V to 5.5 V

supply. The input voltage on the ADC channels has a range of

0 V to 2.25 V and the input bandwidth is dc. The reference for

the ADC channels is derived internally. The ADT7411 provides

two serial interface options: a 4-wire serial interface compatible

with SPI, QSPI, MICROWIRE, and DSP interface standards,

and a 2-wire SMBus/I

C interface. It features a standby mode

that is controlled via the serial interface.

The ADT7411’s wide supply voltage range, low supply current,

and S

PI-/I

C-compatible interface make it ideal for a variety of

applications, including PCs, office equipment, and domestic

appliances.

Protected by U.S. Patent Numbers: 6,169,442; 5,867,012; 5,764174.

Summary of content (36 pages)

PAGE 1
SPI®-/I2C®-Compatible, 10-Bit Digital Temperature Sensor and 8-Channel ADC ADT7411 PIN CONFIGURATION 10-bit temperature-to-digital converter 10-bit 8-channel ADC DC input bandwidth Input range: 0 V to 2.25 V and 0 V to VDD Temperature range: −40°C to +120°C Temperature sensor accuracy of ±0.5°C Supply range: 2.7 V to 5.5 V Power-down current : <10 μA Internal 2.
PAGE 2
ADT7411 TABLE OF CONTENTS Features .............................................................................................. 1 Theory of Operation ...................................................................... 13 Applications....................................................................................... 1 Power-Up Calibration................................................................ 13 Pin Configuration...........................................................................
PAGE 3
ADT7411 SPECIFICATIONS VDD = 2.7 V to 5.5 V, GND = 0 V, unless otherwise noted. Temperature ranges are −40°C to +120°C. Table 1. Parameter 1 ADC DC ACCURACY Resolution Total Unadjusted Error (TUE) Offset Error Gain Error ADC BANDWIDTH ANALOG INPUTS Input Voltage Range DC Leakage Current Input Capacitance Input Resistance THERMAL CHARACTERISTICS Internal Temperature Sensor Accuracy @ VDD = 3.3 V ± 10% Accuracy @ VDD = 5 V ± 5% Resolution Long-Term Drift External Temperature Sensor Accuracy @ VDD = 3.
PAGE 4
ADT7411 Parameter 1 ROUND ROBIN UPDATE RATE 2 Min Slow ADC @ 25°C Averaging On Averaging Off Averaging On Averaging Off Fast ADC @ 25°C Averaging On Averaging Off Averaging On Averaging Off ON-CHIP REFERENCE 3 Reference Voltage Temperature Coefficient DIGITAL INPUTS1, 3 Input Current VIL, Input Low Voltage VIH, Input High Voltage Pin Capacitance SCL, SDA Glitch Rejection 2.2662 Unit Conditions/Comments Time to complete one measurement cycle through all channels. 125.4 17.1 140.36 12.
PAGE 5
ADT7411 Parameter 1 POWER REQUIREMENTS VDD VDD Settling Time IDD (Normal Mode) 8 Min Typ 2.7 2.2 IDD (Power-Down Mode) Power Dissipation Max Unit Conditions/Comments 5.5 50 3 3 10 10 10 33 V ms mA mA μA μA mW μW VDD settles to within 10% of its final voltage level. VDD = 3.3 V, VIH = VDD and VIL = GND. VDD = 5 V, VIH = VDD and VIL = GND. VDD = 3.3 V, VIH = VDD and VIL = GND. VDD = 5 V, VIH = VDD and VIL = GND. VDD = 3.3 V. Using normal mode. VDD = 3.3 V. Using shutdown mode.
PAGE 6
ADT7411 FUNCTIONAL BLOCK DIAGRAM ADT7411 INTERNAL TEMPERATURE VALUE REGISTER D+/AIN1 7 D–/AIN2 8 A-TO-D CONVERTER AIN3 9 THIGH LIMIT REGISTERS LIMIT COMPARATOR DIGITAL MUX EXTERNAL TEMPERATURE VALUE REGISTER ADDRESS POINTER REGISTER DIGITAL MUX ON-CHIP TEMPERATURE SENSOR AIN4 14 ANALOG MUX CONTROL CONFIG. 1 REGISTER AIN1 VALUE REGISTER AIN7 16 CONTROL CONFIG.
PAGE 7
ADT7411 ABSOLUTE MAXIMUM RATINGS Table 3. I2C Address Selection Table 2.
PAGE 8
ADT7411 PIN CONFIGURATION AND FUNCTIONAL DESCRIPTIONS AIN6 1 16 AIN7 AIN5 2 15 AIN8 NC 3 ADT7411 CS 4 TOP VIEW (Not to Scale) VDD 6 D+/AIN1 7 D–/AIN2 8 13 SCL/SCLK 12 SDA/DIN 11 DOUT/ADD 10 INT/INT 9 AIN3 NC = NO CONNECT 02882-005 GND 5 14 AIN4 Figure 6. Pin Configuration Table 4. Pin Function Descriptions Pin No.
PAGE 9
ADT7411 TERMINOLOGY Relative Accuracy Relative accuracy or integral nonlinearity (INL) is a measure of the maximum deviation, in LSBs, from a straight line passing through the endpoints of the ADC transfer function. A typical INL vs. code plot can be seen in Figure 10. Total Unadjusted Error (TUE) Total unadjusted error is a comprehensive specification that includes the sum of the relative accuracy error, gain error, and offset error under a specified set of conditions.
PAGE 10
ADT7411 TYPICAL PERFORMANCE CHARACTERISTICS 2.00 1.0 ADC OFF 0.8 1.95 0.6 INL ERROR (LSB) ICC (mA) 0.4 1.90 1.85 1.80 0.2 0 –0.2 –0.4 –0.6 02882-006 –1.0 0 200 Figure 7. Supply Current vs. Supply Voltage at 25°C 800 1000 Figure 10. ADC INL with Ref = VDD (3.3 V) 0 1.5 ±100mV RIPPLE ON VCC VREF = 2.25V VDD = 3.3V TEMPERATURE = 25°C EXTERNAL TEMPERATURE @ 5V INTERNAL TEMPERATURE @ 3.3V 1.0 TEMPERATURE ERROR (°C) –10 AC PSRR (dB) 400 600 ADC CODE 02882-009 –0.8 1.75 2.7 2.9 3.1 3.
PAGE 11
ADT7411 15 10 VDD = 3.3V –10 5 TEMPERATURE ERROR (°C) D+ TO GND 0 –5 D+ TO VCC –10 –15 –20 –30 –40 0 10 20 30 40 50 60 70 80 90 100 PCB LEAKAGE RESISTANCE (MΩ) –60 02882-012 –25 Figure 13. External Temperature Error vs. PCB Leakage Resistance 10 15 20 25 30 35 40 45 50 Figure 16. External Temperature Error vs. Capacitance Between D+ and D− 70 VDD = 3.3V COMMON-MODE VOLTAGE = 100mV VDD = 3.
PAGE 12
ADT7411 140 EXTERNAL TEMPERATURE 100 INTERNAL TEMPERATURE 80 60 40 TEMPERATURE OF ENVIRONMENT CHANGED HERE 20 0 0 10 20 30 TIME (s) 40 50 60 02882-018 TEMPERATURE (°C) 120 Figure 19. Temperature Sensor Response to Thermal Shock Rev.
PAGE 13
ADT7411 THEORY OF OPERATION After the power-up calibration routine, the ADT7411 goes into idle mode. In this mode, the device is not performing any measurements and is fully powered up. To begin monitoring, write to the Control Configuration 1 register (Address 18h) and set Bit C0 = 1. The ADT7411 goes into its power-up default measurement mode, which is round robin. The device performs measurements in the following channel sequence: 1. VDD channel 2. Internal temperature sensor channel 3.
PAGE 14
ADT7411 FUNCTIONAL DESCRIPTION INT VREF ANALOG INPUTS A The ADT7411 offers eight single-ended analog input channels. The analog input range is from 0 V to 2.25 V or 0 V to VDD. To maintain the linearity specification, it is recommended that the maximum VDD value be set at 5 V. Selection between the two input ranges is done by Bit C4 of the Control Configuration 3 register (Address 1Ah). Setting this bit to 0 sets up the analog input ADC reference to be sourced from the internal voltage reference of 2.
PAGE 15
ADT7411 VDD ADC Transfer Function I The output coding of the ADT7411 analog inputs is straight binary. The designed code transitions occur midway between successive integer LSB values (that is, 1/2 LSB, 3/2 LSB). The LSB is VDD/1024 or Int VREF/1024, Int VREF = 2.25 V. The ideal transfer characteristic is shown in Figure 24. IBIAS VOUT+ TO ADC INTERNAL SENSE TRANSISTOR BIAS DIODE VOUT– 02882-024 111...111 111...110 Figure 25. Top Level Structure of Internal Temperature Sensor 111...000 011...
PAGE 16
ADT7411 The measured results from the temperature sensors are compared with the internal and external THIGH and TLOW limits. These temperature limits are stored in on-chip registers. If the temperature limits are not masked out, any out-of-limit comparisons generate flags that are stored in Interrupt Status 1 register. One or more out-of-limit results causes the INT/INT output to pull either high or low, depending on the output polarity setting.
PAGE 17
ADT7411 VDD Monitoring On-Chip Reference The ADT7411 also has the capability of monitoring its own power supply. The part measures the voltage on its VDD pin to a resolution of 10 bits. The resulting value is stored in two 8-bit registers, with the 2 LSBs stored in register Address 03h and the 8 MSBs stored in register Address 06h. This allows the user to have the option of just doing a 1-byte read if 10-bit resolution is not important. The measured result is compared with the VHIGH and VLOW limits.
PAGE 18
ADT7411 Temperature Measurement Method Internal Temperature Measurement environment, C1 is provided as a noise filter. See the Layout Considerations section for more information on C1. The ADT7411 contains an on-chip, band gap temperature sensor whose output is digitized by the on-chip ADC. The temperature data is stored in the internal temperature value register. As both positive and negative temperatures can be measured, the temperature data is stored in twos complement format, as shown in Table 6.
PAGE 19
ADT7411 Interrupts Place 0.1 μF bypass and 2200 pF input filter capacitors close to the ADT7411. 6. If the distance to the remote sensor is more than 8 inches, the use of twisted-pair cable is recommended. This works up to about 6 feet to 12 feet. 7. For long distances (up to 100 feet) use shielded twistedpair cable, such as Belden #8451 microphone cable. Connect the twisted pair to D+ and D− and the shield to GND close to the ADT7411.
PAGE 20
ADT7411 MSB REGISTER OUTPUT DATA UNLOCK ASSOCIATED MSB REGISTERS 02882-029 SECOND READ COMMAND Figure 30. Phase 2 of 10-Bit Read If an MSB register is read first, its corresponding LSB register is not locked out, thus leaving the user with the option of just reading back 8 bits (MSB) of a 10-bit conversion result. Reading an MSB register first does not lock out other MSB registers, and likewise reading an LSB register first does not lock out other LSB registers. Table 7.
PAGE 21
ADT7411 Table 9. Bit D0 D1 D2 D3 D4 D5 D6 D7 Function 1 when internal temperature value exceeds THIGH limit. Any internal temperature reading greater than the set limit causes an out-of-limit event. 1 when internal temperature value exceeds TLOW limit. Any internal temperature reading less than or equal to the set limit causes an out-of-limit event. This status bit is linked to the configuration of Pin 7 and Pin 8.
PAGE 22
ADT7411 AIN5 to AIN8 Registers LSBs (Read-Only) [Address = 05h] AIN2 Register MSBs (Read) [Address = 09h] This is an 8-bit read-only register. Bit D0 to Bit D7 store the two LSBs of the analog inputs AIN5 to AIN8. The MSBs are stored in Register 0Ch to Register 0Fh. This 8-bit read register contains the eight MSBs of the AIN2 analog input voltage word.
PAGE 23
ADT7411 AIN6 Register MSBs (Read) [Address = 0Dh] Table 29. This 8-bit read register contains the eight MSBs of the AIN6 analog input voltage word. The value in this register is combined with Bit D2 and Bit D3 of the AIN5 to AIN8 register LSBs, Address 05h, to give the full 10-bit conversion result of the analog value on the AIN6 pin. Bit C0 Table 25. AIN6 MSBs D7 MSB 01 1 D6 A8 01 D5 A7 01 D4 A6 01 D3 A5 01 D2 A4 01 D1 A3 01 D0 A2 01 C2:C1 Default settings at power-up.
PAGE 24
ADT7411 Table 31. Table 33. Bit C3:C0 Bit C0 C4 C5 C6 C7 Function In single-channel mode, these bits select between VDD, the internal temperature sensor, external temperature sensor/AIN1, AIN2 to AIN8 for conversion. The default is VDD. 0000 = VDD. 0001 = Internal Temperature Sensor. 0010 = External Temperature Sensor/AIN1. (Bit C1 and Bit C2 of Control Configuration 1 affect this selection.) 0011 = AIN2. 0100 = AIN3. 0101 = AIN4. 0110 = AIN5. 0111 = AIN6. 1000 = AIN7. 1001 = AIN8.
PAGE 25
ADT7411 Interrupt Mask 2 Register (Read/Write) [Address = 1Eh] This mask register is an 8-bit read/write register that can be used to mask out any interrupts that can cause the INT/INT pin to go active. Table 36. Interrupt Mask 2 D7 D7 01 1 D6 D6 01 D5 D5 01 D4 D4 01 D3 D3 01 D2 D2 01 D1 D1 01 D0 D0 01 Default settings at power-up.
PAGE 26
ADT7411 Internal TLOW Limit Register (Read/Write) [Address = 26h] This limit register is an 8-bit read/write register that stores the twos complement of the internal temperature lower limit that causes an interrupt and activates the INT/INT output (if enabled). For this to happen, the measured internal temperature value has to be more negative than or equal to the value in this register. Because it is an 8-bit register, the temperature resolution is 1°C. The default value is −55°C.
PAGE 27
ADT7411 AIN2 VLOW Limit Register (Read/Write) [Address = 2Ch] Table 50. AIN4 VHIGH Limit This limit register is an 8-bit read/write register that stores the AIN2 input lower limit that causes an interrupt and activates the INT/INT output (if enabled). For this to happen, the measured AIN2 value has to be less than or equal to the value in this register. Because it is an 8-bit register, the resolution is four times less than the resolution of the 10-bit ADC. The default value is 0 V. D7 D7 11 Table 47.
PAGE 28
ADT7411 AIN6 VHIGH Limit Register (Read/Write) [Address = 33h] Table 57. AIN7 VLOW Limit This limit register is an 8-bit read/write register that stores the AIN3 input upper limit that causes an interrupt and activates the INT/INT output (if enabled). For this to happen, the measured AIN6 value has to be greater than the value in this register. Because it is an 8-bit register, the resolution is four times less than the resolution of the 10-bit ADC. The default value is full-scale voltage.
PAGE 29
ADT7411 SPI Lock Status Register (Read-Only) [Address = 7Fh] LOCK AND SELECT SPI ADT7411 Bit D0 (LSB) of this read-only register indicates whether the SPI interface is locked or not. Writing to this register causes the device to malfunction. CS VDD Default value is 00h. 0 = I2C interface. 1 = SPI interface selected and locked. 820Ω 820Ω 820Ω SPI FRAMING EDGE SERIAL INTERFACE DOUT 2 There are two serial interfaces that can be used on this part: I C and SPI.
PAGE 30
ADT7411 The peripheral whose address corresponds to the transmitted address responds by pulling the data line low during the low period before the ninth clock pulse, known as the acknowledge bit. All other devices on the bus now remain idle while the selected device waits for data to be read from or written to it. If the R/W bit is 0, the master writes to the slave device. If the R/W bit is 1, the master reads from the slave device. 2.
PAGE 31
ADT7411 30ns MIN C B SPI LOCKED ON THIRD RISING EDGE 30ns MIN A CS (START LOW) SPI FRAMING EDGE C B SPI LOCKED ON THIRD RISING EDGE 02882-032 A CS (START HIGH) SPI FRAMING EDGE Figure 33. Serial Interface—Selecting and Locking SPI Protocol 1 9 1 9 SCL 0 0 1 A2 A0 A1 R/W START BY MASTER P7 P6 P5 P4 P3 P2 P1 P0 ACK. BY ADT7411 ACK. BY ADT7411 FRAME 1 SERIAL BUS ADDRESS BYTE STOP BY MASTER FRAME 2 ADDRESS POINTER REGISTER BYTE Figure 34.
PAGE 32
ADT7411 The part operates in a slave mode and requires an externally applied serial clock to the SCLK input. The serial interface is designed to allow the part to be interfaced to systems that provide a serial clock that is synchronized to the serial data. Multiple data reads are possible in SPI interface mode as the address pointer register is auto-incremental. The address pointer register auto-increments from 00h to 3Fh and loops back to start over again at 00h when it reaches 3Fh.
PAGE 33
ADT7411 CS 1 8 8 1 SCLK DIN D6 D7 D5 D3 D4 D2 D1 D7 D0 D6 D5 D4 D3 D2 D1 D0 START WRITE COMMAND REGISTER ADDRESS CS (CONTINUED) 1 8 SCLK (CONTINUED) D7 DIN (CONTINUED) D6 D4 D5 D3 D2 D1 D0 02882-036 STOP DATA BYTE Figure 37.
PAGE 34
ADT7411 CS 1 8 8 1 SCLK DIN DOUT D7 D6 D5 D4 D3 D2 D1 D0 X X X X X X X X X X X X X X X X D7 D6 D5 D4 D3 D2 D1 D0 START READ COMMAND DATA BYTE 1 CS (CONTINUED) 1 8 SCLK (CONTINUED) DIN (CONTINUED) DOUT (CONTINUED) X X X X X X X X D7 D6 D5 D4 D3 D2 D1 D0 02882-039 STOP DATA BYTE 2 Figure 40. SPI—Reading Two Bytes of Data from Two Sequential Registers SPI READ OPERATION 02882-040 CS WRITE OPERATION Figure 41.
PAGE 35
ADT7411 OUTLINE DIMENSIONS 0.197 0.193 0.189 9 16 0.158 0.154 0.150 1 8 0.244 0.236 0.228 PIN 1 0.069 0.053 0.065 0.049 0.010 0.025 0.004 BSC COPLANARITY 0.004 0.012 0.008 SEATING PLANE 0.010 0.006 8° 0° 0.050 0.016 COMPLIANT TO JEDEC STANDARDS MO-137-AB Figure 44.
PAGE 36
ADT7411 NOTES Purchase of licensed I2C components of Analog Devices, Inc. or one of its sublicensed Associated Companies conveys a license for the purchaser under the Philips I2C Patent Rights to use these components in an I2C system, provided that the system conforms to the I2C Standard Specification as defined by Philips. ©2006 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. C02882-0-12/06(B) Rev.