SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 FEATURES D Multifunction Monitoring Integrated Circuit D D D D D D D D D D D D DESCRIPTION Designed to Work With an Intelligent Host Controller : − Provides State of Charge Information for Rechargeable Batteries − Provides Accurate Battery Voltage and Temperature Measurement High Accuracy Coulometric Charge and Discharge Current Integration With Automatic Offset Compensation 11-Bit Analog-to-Digital Converter Reports Battery Voltage With Gain and Offset Correction Differential Current Sense 32 Bytes of General Purpose RAM 96 Bytes of Flash (Including 32 Bytes of Shadow Flash) 8 Bytes of ID ROM Internal Temperature Sensor Eliminates the Need for an External Thermistor Programmable Digital Input/Output Port High-Accuracy Internal Timebase Eliminates External Crystal Oscillator Low Power Consumption: − Operating : 30 µA − Sleep: 1 µA − Hibernate: 600 nA Single-Wire HDQ Serial Interface Packaging: 8-LEAD TSSOP The bq26220 is an advanced battery monitoring device designed to accurately measure the charge and discharge currents in rechargeable battery packs. Intended for pack integration, the bq26220 contains all the necessary functions to form the basis of a comprehensive battery capacity management system in portable applications such as cellular phones, PDA’s, or other portable products. The bq26220 works with the host controller in the portable system to implement the battery management system. The host controller is responsible for interpreting the bq26220 data and communicating meaningful battery data to the end-user or power management system. This device provides 64 bytes of general-purpose flash memory, 8 bytes of ID ROM and 32 bytes of flash-backed RAM for data storage. The nonvolatile memory can maintain formatted battery monitor information, identification codes, warranty information, or other critical battery parameters during periods when the battery is temporarily shorted or deeply discharged. PW PACKAGE (TOP VIEW) RBI VCC VSS HDQ 1 2 3 4 8 7 6 5 GPIO SRP SRN BAT Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. !"#$%! & '("")% $& ! *(+'$%! ,$%)"!,('%& '!!"# %! &*)''$%!& *)" %.) %)"#& ! )/$& &%"(#)%& &%$,$", 0$""$%1- "!,('%! *"!')&&2 ,!)& !% )')&&$"+1 '+(,) %)&%2 ! $++ *$"$#)%)"&- Copyright 2002, Texas Instruments Incorporated www.ti.com 1 SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 ORDERING INFORMATION{ TA −20_C to 70_C PACKAGE PART NUMBER TSSOP bq26220PW TOP MARKING 26220 † PW (TSSOP−8) package is available taped and reeled. Add R suffix to device type (e.g. bq26220PWR) to order quantities of 2000 devices per reel for TSSOP-8. ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range (unless otherwise noted)(1) bq26220 Supply voltage (VCC with respect to GND) UNIT −0.3 to +7.0 Input voltage, SRP and SRN, RBI, GPIO and BAT (all with respect to GND) −0.3 V to VCC + 0.3 V Input voltage, HDQ (with respect to GND) V −0.3 to +7.0 Output current (GPIO) 5 Output current (HDQ) 5 Operating free-air temperature range, TA mA −20°C to 70°C Storage temperature range, Tstg °C C − 65°C to 150°C Lead temperature (soldering, 10 s) 300 (1) Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, and operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability RECOMMENDED OPERATING CONDITIONS PARAMETER MIN MAX UNIT VCC V(POR) Supply voltage 2.8 4.5 V Power-on reset voltage 1.9 2.45 V TA Operating ambient temperature −20 70 _C 2 www.ti.com SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 dc electrical characteristics over recommended operating temperature and supply voltage (unless otherwise noted) PARAMETER ICC(OP) I(SLEEP) TEST CONDITIONS Supply current Sleep current I(HIBERNATE) Hibernate current ICC(PROG) Flash programming supply current ICC(ERASE) Flash erase supply current I(RBI) Register back-up current IOL VIL MIN VCC = 4.3 V, flash programming not active VCC = 4.3 V, flash programming not active Digital output low sink current, GPIO and HDQ pins TYP 1 5 600 VCC = 5.5 VCC = 5.5 21 30 21 30 1.2 V< VCC < V(POR) Digital input high, GPIO and HDQ pins RBAT BAT input impedance RSR SRP, SRN input impedance µA A nA mA 25 nA 1 mA VOL = 0.4 V Digital input low, GPIO and HDQ pins VIH UNIT 37 0 < VCC < VPOR RBI pin only, MAX 30 0.7 VCC < 4.2 V VCC > 4.2 V 1.7 V 1.9 10 M MΩ 10 0.2 V < (V(SRP) − V(SRN)) < VCC timer characteristics over recommended operating temperature and supply voltage (unless otherwise noted) PARAMETER E(TMR) TEST CONDITIONS Timer accuracy error MIN TYP −4% MAX UNIT 4% temperature register characteristics over recommended operating temperature and supply voltage (unless otherwise noted) PARAMETER T(RES) E(T) TEST CONDITIONS MIN Reported temperature resolution Reported temperature accuracy BQ26220PW TYP MAX UNIT 0.25 TSSOP package −4 4 _K voltage ADC specification, over recommended operating temperature and supply voltage, (unless otherwise noted) PARAMETER Least significant bit (LSB)(1) TEST CONDITIONS MIN 2.6 V ≤ VBAT ≤ 4.5 V Integral nonlinearity (INL) 2.6 V ≤ VBAT ≤ 4.5 V, Vcc=VBAT −4 Differential nonlinearity (DNL) 2.6 V ≤ VBAT ≤ 4.5 V, Vcc=VBAT Offset error 2.6 V ≤ VBAT ≤ 4.5 V, Vcc=VBAT Maximum error 2.6 V ≤ VBAT ≤ 4.5 V, Vcc=VBAT TYP MAX UNIT +4 LSB −1 +1 LSB −3 +14 LSB −9 +15 LSB 2.44 mV NOTE 1. For a more detailed explantion of parameters refer to the application note, Understanding Data Converters, TI Literature No. SLAA013. www.ti.com 3 SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 VFC characteristics over recommended operating temperature and supply voltage (unless otherwise noted) PARAMETER TEST CONDITIONS VI(SR) G(VFC) Input voltage VSRP − VSRN G(VCC) Supply voltage gain coefficient G(TCO) Temperature gain coefficient INL Integrated nonlinearity −100 mV < (V(SRP) − V(SRN)) < 100 mV V(COS) Auto compensated offset 2.8 V ≤ VCC ≤ 4.2 V Charge/discharge gain MIN TYP −100 Temperature = 25 _C, VCC = 3.6 −100 mV < (V(SRP) − V(SRN)) < 100 mV 88 −20 91 MAX UNIT 100 mV 94 Hz/V 0.5 %/V 0.005 %/_C 0.2% 0.5% −1 20 µV flash memory characteristics over recommended operating temperature and supply voltage (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX Data retention 5 Flash programming write-cycles t(BYTEPROG) Byte programming time RAM-to-flash block programming t(BLCKPROG) time t(BLKERASE) Block-erase time UNIT 10,000 Years Cycles 90 60 µs + 30 µs/byte 1020 60 µs + 30 µs/byte 1020 µs standard serial communication (HDQ) timing specification over recommended operating temperature and supply voltage (unless otherwise noted). See Figures 1 and 2. PARAMETER TEST CONDITIONS MIN TYP MAX T(B) T(BR) Break timing Break recovery 40 T(CYCH) T(HW1) Host bit window 190 Host sends 1 32 50 T(HW0) T(RSPS) Host sends 0 100 145 bq26220 to host response 190 320 190 250 T(CYCB) bq26220 bit window T(start−detect) (1) T(DW1) T(DW0) UNIT 190 5 µs ns bq26220, sends 1 32 50 bq26220, sends 0 80 145 µss NOTE 1. The HDQ engine of the bq26220 interpret a 5 ns or longer glitch on HDQ as a bit start. A sufficient number of glitches at 5 ns or longer could result in incorrect data being written to the device. The HDQ line should be properly deglitched to ensure that this does not occur. 4 www.ti.com SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 PARAMETER MEASUREMENT INFORMATION T(B) T(BR) T(CYCH) T(HW1) T(HW0) T(CYCB) T(DW1) T(DW0) Figure 1. HDQ Timing Diagram COMMAND BYTE (Written by Host to bq26220) BREAK DATA BYTE (Received by Host From bq26220) REGISTER ADDRESS 0 (LSB) 1 2 3 4 5 6 0 (LSB) 7 (MSB) 1 2 3 4 5 6 7 (MSB) t(RSPS) Figure 2. Typical Communication with the bq26220 www.ti.com 5 SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 FUNCTIONAL BLOCK DIAGRAM Bandgap, Reference and Bias VCC SRP Temperature Compensated Precision Oscillator Autocalibrating VFC SRN Timer System I/O and Control User Registers RAM GPIO HDQ RBI Temperature Sensor Flash Multiplexer ADC BAT ID VSS UDG−02050 TERMINAL FUNCTIONS TERMINAL DESCRIPTION No. BAT 5 I Battery voltage sense input. This pin is used for sensing and measuring the battery voltage. RBI 1 I Register backup input. The RBI input pin is used with a storage capacitor or external supply to provide backup potential to the internal RAM and registers while VCC is < V(POR). GPIO 8 I/O General-purpose input/output pin. GPIO is a general-purpose programmable input or output port whose state is controlled via the HDQ serial communications interface. HDQ 4 I/O Single-wire HDQ interface. HDQ is a single-wire serial communications interface port. This bidirectional input/output communicates the register information to the host. SRN 6 I/O NAME 6 I Current sense input 2. The bq26220 interprets charge and discharge activity by monitoring and integrating the voltage drop, VSR, across pins SRP and SRN. The SRN input connects to the sense resistor and the negative terminal of the pack. VSRP < VSRN indicates discharge, and VSRP > VSRN indicates charge. I Current sense input 1. The bq26220 interprets charge and discharge activity by monitoring and integrating the voltage drop, VSR, across pins SRP and SRN. The SRP input connects to the sense resistor and the negative terminal of the battery. VSRP < VSRN indicates discharge, and VSRP > VSRN indicates charge. SRP 7 VCC 2 I Supply voltage VSS 3 − Ground www.ti.com SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 APPLICATION INFORMATION PACK+ U1 C4 0.1 µF C3 0.1 µF + bq26220PW 1 RBI GPIO 8 R2 100 kΩ Additional ESD Protection R5 R4 100 Ω 100 Ω HDQ 2 VCC SRP 7 3 VSS SRN 6 4 HDQ BAT 5 D1 5.6 V C1 0.1 µF R3 100 kΩ R1 0.02 Ω C2 0.1 µF Protection Controller PACK− UDG−04012 Figure 3. Typical Application Circuit for a Single-Cell Li-Ion Application functional description The bq26220 measures the voltage drop across a low-value series current-sense resistor between the SRP and SRN pins using a voltage-to-frequency converter. The cell voltage is sensed between the BAT and VSS pins. All data is placed into various internal counter and timer registers. Using information from the bq26220, the system host can determine the battery state-of-charge, estimate self discharge, and calculate the average charge and discharge currents. During pack storage periods, the use of an internal temperature sensor doubles the self-discharge count rate every 10°C above 25°C. The VFC offset is automatically compensated for in the charge and discharge counter registers. Access to the registers and control of the bq26220 is accomplished through a single-wire interface through a register mapped command protocol. This protocol includes placing the device in the low-power mode, hardware-register reset, programming flash from RAM, and transferring flash data to RAM. The bq26220 can operate directly from a single Li-Ion cell as long as VCC is between 2.8 V and 4.5 V. www.ti.com 7 SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 APPLICATION INFORMATION charge and discharge count operation Table 1 shows the main counters and registers of the bq26220. The bq26220 accumulates charge and discharge counts into two count registers, the charge count register (CCR) and the discharge count register (DCR). Charge and discharge counts are generated by sensing the voltage difference between SRP and SRN. The CCR or DCR independently counts, depending on the signal between pins SRP and SRN. During discharge, the DCR and the discharge time counter (DTC) are active. If (V(SRP) − V(SRN)) is less than 0, (indicating a discharge activity), the DCR counts at a rate equivalent to one count per 3.05 µVH, and the DTC counts at a rate of 1.138 counts per second (4096 counts = 1 hour). For example, if no rollover of the DTC register is incipient, a negative 24.42-mV signal produces 8000 DCR counts and 4096 DTC counts each hour. The amount of charge removed from the battery is easily calculated. During charge, the CCR and the charge time counter (CTC) are active. If (V(SRP) − V(SRN)) is greater than 0, (indicating a charge), the CCR counts at a rate equivalent to one count per 3.05 µVH, and the CTC counts at a rate of 1.138 counts per seconds. In this case a 24.42-mV signal produces 8000 CCR counts and 4096 CTC counts (assuming no rollover) each hour. The DTC and the CTC are 16-bit registers, with roll over beyond FFFFH. If a rollover occurs, the corresponding bit in the MODE register is set, and the counter increments at 1/256 of the normal rate (16 counts per hour). While in normal operation, the internal RAM and flash registers of the bq26220 may be accessed over the HDQ pin. For self-discharge calculation, the self-discharge count register (SCR) counts at a rate of one count every hour at a nominal 25°C. The SCR count rate doubles approximately every 10°C up to 60°C. The SCR count rate is halved every 10°C below 25°C down to 0°C. The value in SCR is useful in estimating the battery self-discharge based on capacity and storage temperature conditions. Table 4 shows the bq26220 register memory map. The remaining memory can store user-specific information such as chemistry, serial number, and manufacturing date. sleep mode operation The bq26220 begins low-power operation in response to the host issuing the sleep command. Before entering the low-power state, the host processor writes the command to transfer the registers to flash. After the sleep command is sent and the charge/discharge activity is less than the value indicated by the WOE bits shown in Table 2, the chip clock is powered down and data acquisitions functions cease except for self-discharge detection. During device sleep the bq26220 periodically wakes briefly to maintain the self-discharge registers. The bq26220 wakes on either a low-to-high or high-to-low transition on the HDQ pin. Table 3 shows which registers are active during normal operation, sleep, and hibernate. Table 1. bq26220 Counters NAME 8 DESCRIPTION RANGE RAM SIZE (BITS) 16 Charge count register (V(SRP) − V(SRN)) < VSS (Max. =−100 mV) 3.05 µV/LSB (V(SRP) − V(SRN)) > VSS (Max. = 100 mV) 3.05 µV/LSB Self-discharge count register 1 count/hour at 25°C 16 DCR Discharge count register CCR SCR DTC Discharge time counter CTC Charge time counter 1 count/0.8789 s (default) 1 count/225 s if STD is set 1 count/0.8789 s (default) 1 count/225 s if STC is set www.ti.com 16 16 16 SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 APPLICATION INFORMATION Table 2. WOE Thresholds WOE3–1 (HEX) 0h VWOE (mV) n/a 1h 3.516 2h 1.758 3h 1.172 4h 0.879 5h 0.703 6h 0.586 7h 0.502 Table 3. Operational States MODE ACTIVE REGISTERS Normal CCR, DCR, CTC, DTC, SDR Sleep SDR Hibernate No active registers hibernate mode operation The bq26220 enters hibernate mode when Vcc drops below the POR threshold, V(POR). In this mode, the bq26220 draws current from the RBI pin to maintain RAM data. The bq26220 exits hibernate mode only when Vcc is raised above the POR threshold. current sense offset calibration and compensation The bq26220 automatically and continuously compensates for V(SRP) − V(SRN) offset. No host calibration or compensation is required. gas gauge control registers The host maintains the charge and discharge and the self-discharge count registers (CCR, CTC, DCR, DTC, and SCR). To facilitate this maintenance, the bq26220 CLR register resets the specific counter or register pair to zero. The host system clears a register by writing the corresponding register bit to 1. When the bq26220 completes the reset, the corresponding bit in the CLR register is automatically reset to 0. Clearing the DTC or CTC registers clears the MODE register bits STC/STD and sets the CTC/DTC count rates to the default value of 1.138 counts per second. device temperature measurement The bq26220 reports die temperature in units of oK through register pair TMPH−TMPL. Refer to the TMP register description for more details. www.ti.com 9 SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 APPLICATION INFORMATION battery voltage measurement The bq26220 senses the battery voltage on the BAT pin and reports it through register pair BATH−BATL. The BATH (address = 0x72 – bits 0 through 2) and the BATL low-byte register (address = 0x71) contain the result of ADC conversion on the battery voltage. The voltage is expressed in an 11-bit binary format with an LSB step size of 2.44 mV. Bit 2 of BATH register represents the MSB and bit 0 of the BATL represent the LSB. The full-scale voltage for this measurement is 5 V and is optimized for direct sensing in single-cell Li-Ion or Li-pol applications (see Figure 3). Note that Bits 3 through 7 of the BATH register store the offset information for the voltage ADC. The most significant bit is the sign-bit followed by 4 bits of offset data. Also note that LSB gain correction factor, in µV, is stored in address 0x79 (byte 1 of the ID ROM) in 2’s complement. The host is responsible for applying the LSB gain correction factor and offset to the ADC measurements. Correct VBAT = VBAT × (2.44 + LSB correction factor) − offset example 1: (If real LSB = + 2.45mV and offset = +80 mV) in address 0x79 ⇒ 0000 1010 (in binary) 2’s complement in BATH (0x72) ⇒ 0101 0XXX (in binary) signed magnitude To calculate the correct VBAT: LSB correction factor = +10 µV = +0.01 mV offset = +10 × 8 mV = 80 mV Correct VBAT (in mV) = VBAT × (2.44 + 0.01) − 80 example 2: (If real LSB = +2.43 mV and offset = −80 mV in address 0x79 ⇒ 1111 0110 (in binary), 2’s complement in BATH (0x72) ⇒ 1101 0XXX (in binary), signed magnitude To calculate the correct VBAT: LSB correction factor = −10 µV= −0.01 mV offset = −10 × 8 mV = −80 mV Correct VBAT (in mV) = VBAT × (2.44 − 0.01) − (−80) 10 www.ti.com SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 APPLICATION INFORMATION register interface Information is exchanged between host system and the bq26220 through the data-register interface. See Table 4 below. The register set consists of a 122-location address space of 8-bit bytes segmented into • • • • 8 bytes of factory programmed ID ROM 32 bytes of flash shadowed RAM 64 bytes of general purpose flash 18 special function registers Table 4. Memory Map HDQ ADDRESS NAME BIT7 BIT6 BIT5 BIT4 BIT3 BIT2 BIT1 BIT0 0x78−0x7F IDROM 8 bytes of factory-programmed ROM and gain correction factor for BATH and BATL 0x73−0x77 − Reserved 0x72 BATH BV−SIGN 0x71 BATL Battery voltage (bits 0 through 7) 0x70 FPA Flash program address byte 0x6F FPD Flash program data byte 0x6E DCRH Discharge count register-high byte 0x6D DCRL Discharge count register-low byte 0x6C CCRH Charge count register-high byte 0x6B CCRL Charge count register-low byte 0x6A SCRH Self-discharge count register-high byte 0x69 SCRL Self−discharge count register-low byte 0x68 DTCH Discharge timer counter register-high byte 0x67 DTCL Discharge timer count register-low byte 0x66 CTCH Charge timer counter register-high byte 0x65 CTCL Charge timer counter register-low byte 0x64 MODE GPIEN STAT STC STD WOE2 WOE1 WOE0 POR 0x63 CLR RSVD RSVD RSVD CTC DTC SCR CCR DCR 0x62 FCMD Flash/control command register 0x61 TEMPH Temperature-high byte (bits 0 through 2 only, other bits are reserved) 0x60 TEMPL Temperature-low byte 0x40−0x5F Flash Page 2, 32 bytes of flash 0x20−0x3F Flash Page 1, 32 bytes of flash 0x00−0x1F RAM/flash Page 0, 32 bytes of flash shadowed RAM BVOS3 BVOS2 BVOS1 www.ti.com BVOS0 Battery voltage (bits 8 through 10) 11 SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 APPLICATION INFORMATION memory ID ROM Locations 0x7F through 0x78 contain the factory programmed ID ROM and also the LSB gain correction factor for the voltage analog to digital converter. The format for this register is described in Table 5. Table 5. ID ROM Command Code Summary BYTE RAM LOCATION INFORMATION 7 0x7F Device code 0x22 6 0x7E 0x00 5 0x7D Random 4 0x7C Random 3 0x7B Random 2 0x7A Random 1 0x79 Gain correction factor 0 0x78 Random NOTE:For additional information please contact Texas Instruments. flash-shadowed RAM The host system has direct access to read and modify 32 bytes of RAM. These 32 bytes are shadowed by 32 bytes of flash to provide nonvolatile storage of battery conditions. The information stored in RAM is transferred to flash, and the information stored in flash is transferred to RAM by writing a single command into the flash command register (FCMD). When a power-on-reset occurs, page 0 of flash is transferred to RAM. For more details, refer to the flash command register section. user-flash memory In addition to the flash-shadowed RAM, the bq26220 has 64 bytes of user-flash. The user-flash can store specific battery pack parameters, such as charge per VFC pulse, battery chemistry, and self-discharge rates. flash programming The two banks of direct user-flash are programmed one byte at a time, but the single bank of flash-shadowed RAM can be programmed one page at a time or by writing the RAM-to-flash transfer code into the flash command register (FCMD). This programming is performed by writing the desired code into the flash command register, FCMD (address 0x62), the host may transfer data between flash and RAM, page erase the flash or place the device into the low power mode. For more details, refer to the flash command register section. Summaries of the flash command codes are shown in Table 6. Table 6. Flash Command Code Summary COMMAND CODE (HEX) 12 DESCRIPTION 0x0F Program byte 0x40 Erase page 0 flash 0x41 Erase page 1 flash 0x42 Erase page 2 flash 0x45 Transfer page 0 RAM to page 0 flash 0x48 Transfer page 0 flash to page 0 RAM 0xF6 Power down www.ti.com SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 APPLICATION INFORMATION single-byte programming To program an individual byte in flash, the byte of data is first written into the FPD register while the address to be programmed is written into the FPA register. The program byte command, 0x0F, is then written to the FCMD. The result of this sequence is that the contents of the FPD register is logically ANDed with the contents of the flash address pointed to by the FPA register. RAM-to-flash transfer The content of the flash that shadows the user RAM is logically ANDed to the RAM contents when the RAM-to-flash transfer command is sent. If new data is to be written over old data, then it is necessary to first erase the flash page that is being updated and restore all necessary data. communicating with the bq26220 The bq26220 includes a single-wire HDQ serial data interface. Host processors, configured for either polled or interrupt processing, use the interface to access various bq26220 registers. The HDQ pin requires an external pull-up resistor. The interface uses a command-based protocol, where the host processor sends a command byte to the bq26220. The command directs the bq26220 either to store the next eight bits of data received to a register specified by the command byte, or, to output the eight bits of data from a register specified by the command byte. The communication protocol is asynchronous return-to-one and is referenced to VSS. Command and data bytes consist of a stream of eight bits that have a maximum transmission rate of 5 Kbits/s. The least-significant bit of a command or data byte is transmitted first. Data input from the bq26220 may be sampled using the pulse-width capture timers available on some microcontrollers. A UART, (universal asynchronous receiver transmitter), also communicates with the bq26220. If a communication time out occurs (for example, if the host waits longer than t(CYCB) for the bq26220 to respond or if this is the first access command), then a BREAK should be sent by the host. The host may then resend the command. The bq26220 detects a BREAK when the HDQ pin is driven to a logic-low state for a time t(B) or greater. The HDQ pin then returns to its normal ready-high logic state for a time t(BR).The bq26220 is then ready for a command from the host processor. The return-to-one data-bit frame consists of three distinct sections: 1. The first section starts the transmission by either the host or the bq26220 taking the HDQ pin to a logic-low state for a period equal to t(HW1) or t(DW1). 2. The next section is the actual data transmission, where the data should be valid by a period equal to t(HW1) or t(DW1), after the negative edge that starts communication. The data should be held for t(HW0) and t(DW0) periods to allow the host or bq26220 to sample the data bit. 3. The final section stops the transmission by returning the HDQ pin to a logic-high state by at least a period equal to t(DW0) or t(HW0) after the negative edge used to start communication. The final logic-high state should be held until a period equal to t(CYCH) or t(CYCB), to allow time to ensure that the bit transmission ceased properly. www.ti.com 13 SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 APPLICATION INFORMATION The serial communication timing specification and illustration sections give the timings for data and break communication. Communication with the bq26220 always occurs with the least significant bit being transmitted first. Figure 4 shows an example of a communication sequence to read the bq26220 DCRH register. COMMAND BYTE (Written by Host to bq26220) BREAK DATA BYTE (DCRH) = 64h (Received by Host From bq26220) CMDR=6Eh 0 (LSB) 0 1 2 3 4 5 1 1 1 0 1 6 1 0 (LSB) 7 (MSB) 0 0 1 2 3 4 5 6 0 1 0 0 1 1 7 (MSB) 0 MSB LSB 64h=0 1 1 0 0 1 0 0 MSB LSB 6Eh=0 1 1 0 1 1 1 0 Figure 4. bq26220 Communication Sequence command byte The command byte of the bq26220 consists of eight contiguous valid command bits. The command byte contains two fields: W/R Command and address. The W/R bit of the command register determines whether the command is a read or a write command while the address field containing bit AD6−AD0 indicates the address to be read or written. The command byte values are shown in Table 7. Table 7. Command Byte Values COMMAND BYTE 7 6 5 4 3 2 1 0 W/R AD6 AD5 AD4 AD3 AD2 AD1 AD0 Table 8. Command Byte Definitions Indicates whether the command byte is a read or write command. A 1 indicates a write command and that the following eight bits should be written to the register specified by the address field of the command byte, while a 0 indicates that the command is a read. On a read command, the bq26220 outputs the requested register contents specified by the address field portion of the command byte. W/R AD6−AD0 The seven bits labeled AD6−AD0 containing the address portion of the register to be accessed. bq26220 registers register maintenance The host system is responsible for register maintenance. (See Table 4.) To facilitate this maintenance, the bq26220 clear register (CLR) resets the specific counter or register pair to zero. The host system clears a register by writing the corresponding register bit to 1. When the bq26220 completes the reset, the corresponding bit in the CLR register automatically resets to 0, saving the host an extra write/read cycle. Clearing the DTC register clears the STD bit and sets the DTC count rate to the default value of one count per 0.8789 s. Clearing the CTC register clears the STC bit and sets the CTC count rate to the default value of one count per 0.8789 s. 14 www.ti.com SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 APPLICATION INFORMATION register descriptions battery voltage offset registers (BATH) Bits 3 through 7 of the BATH register (address = 0x72) store the offset information for the voltage ADC. The most significant bit is the sign bit followed by 4 bits of offset data. Each count of offset represents 8 mV. The host is responsible for subtracting the offset for the measurement from the uncorrected value found in BATH and BATL registers. This is a signed magnitude number with Bit 7 being the sign bit. A 1 in Bit 7 means that the number is negative. battery voltage registers (BATH/BATL) The BATH (address = 0x72 – bits 0 through 2) and the BATL low-byte register (address = 0x71) contain the result of ADC conversion on the battery voltage. The voltage is expressed in an 11-bit binary format with an LSB step size of 2.44 mV. Bit 3 of BATH register represents the MSB and bit 0 of the BATL represent the LSB. flash program address register (FPA) The FPA byte register (address = 0x70) points to the flash address location that is programmed when the program flash command is issued. This byte is used with the FPD and FCMD register to program an individual byte in flash memory. flash program data register (FPD) The FPD byte register (address = 0x6F) contains the data to be programmed into the flash address location pointed to by the contents of the FPA register. When the program flash command is issued, the contents of the FPD register are ANDed with the contents of the byte pointed to by the FPA and then stored into that location. discharge count registers (DCRH/DCRL) The DCRH high-byte register (address = 0x6E) and the DCRL low-byte register (address = 0x6D) contain the count of the discharge, and are incremented whenever VSR < VSS These registers continue to count beyond FFFFH, so proper register maintenance by the host system is necessary. The CLR register forces the reset of both the DCRH and DCRL to zero. charge count registers (CCRH/CCRL) The CCRH high-byte register (address = 0x6C) and the CCRL low-byte register (address = 0x6B) contain the count of the charge, and are incremented whenever VSR > VSS. These registers continue to count beyond FFFFH, so proper register maintenance should be done by the host system. The CLR register forces the reset of both the CCRH and CCRL to zero. self-discharge count registers (SCRH/SCRL) The SCRH high-byte register (address = 0x6A) and the SCRL low-byte register (address = 0x69) contain the self-discharge count. This register is continually updated in both the normal operating and sleep modes of the bq26220. The counts in these registers are incremented based on time and temperature. The SCR counts at a rate of one count per hour at 20°C to 30°C. The count rate doubles every 10°C up to a maximum of 16 counts/hour at temperatures above 60°C. The count rate halves every 10°C below 20°C to 30°C to a minimum of one count/8 hours at temperature below 0°C. These registers continue to count beyond FFFFH, so proper register maintenance should be done by the host system. The CLR register forces the reset of both the SCRH and SCRL to zero. During device sleep the bq26220 periodically wake for a brief amount of time to maintain the self-discharge registers. www.ti.com 15 SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 APPLICATION INFORMATION discharge time count registers (DTCH/DTCL) The DTCH high-byte register (address = 0x68) and the DTCL low-byte register (address = 0x67) determine the length of time the VSR < VSS indicating a discharge. The counts in these registers are incremented at a rate of 4096 counts per hour. If the DTCH/DTCL register continues to count beyond FFFFH, the STD bit is set in the MODE/WOE register, indicating a rollover. Once set, DTCH and DTCL increment at a rate of 16 counts per hour. Note: If a second rollover occurs, STD is cleared. Access to the bq26220 should be timed to clear DTCH/DTCL more often than every 170 days. The CLR register forces the reset of both the DTCH and DTCL to zero. charge-time count registers (CTCH/CTCL) The CTCH high-byte register (address = 0x66) and the CTCL low-byte register (address = 0x65) determine the length of time the VSR >VSS, indicating a charge activity. The counts in these registers are incremented at a rate of 4096 counts per hour. If the CTCH/CTCL registers continue to count beyond FFFFH, the STC bit is set in the MODE/WOE register indicating a rollover. Once set, DTCH and DTCL increment at a rate of 16 counts per hour. Note: If a second rollover occurs, STC is cleared. Access to the bq26220 should be timed to clear CTCH/CTCL more often than every 170 days. The CLR register forces the reset of both the CTCH and CTCL to zero. mode register (MODE) The MODE register (address 0x64) contains the GPIEN, STAT, STC, STD, POR and wake-up enable information as described in Table 9. Table 9. MODE Register Values MODE BITS 7 6 5 4 3 2 1 (MSB) GPIEN 0 (LSB) STAT STC STD WOE2 WOE1 WOE0 POR Table 10. MODE Register Definitions GPIEN GPIEN bit (bit 7) sets the state of the GPIO pin. A 1 configures the GPIO pin as input, while a 0 configures the GPIO pin as open-drain output. This bit is set to 0 on power-on-reset. STAT STAT bit (bit 6) sets the state of the open drain output of the GPIO pin (when configured as output by bit 7). A 1 turns off the open drain output while a 0 turns the output on. This bit is set to 1 on power-on-reset. STC & STD WOE[2.0] POR 16 The slow time charge (STC) and slow time discharge (STD) flags indicate if the CTC or DTC registers have rolled over beyond FFFFH. STC set to 1 indicates a CTC rollover; STD set to 1 indicates a DTC rollover. The wake-up output enable (WOE) bits (bits 3, 2 and 1) indicate the voltage level required between SRP and SRN so that the bq26220 enters sleep mode after a power down command is issued. Whenever |VSRP − VSRN| < VWOE, the bq26220 enters sleep mode after the power down command has been issued. On bq26220 power-on-reset these bits are set to 1. Setting all of these bits to zero is valid, but result in immediate sleep. Refer to Table 3 for the various WOE values. POR bit (bit 0) indicates a power-on-reset has occurred. This bit is set when VCC has gone below the POR level. This bit can be also set and cleared by the host, but has no functionality if set by host. www.ti.com SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 APPLICATION INFORMATION clear register (CLR) The bits in the CLR register (address 0x63) clear the DCR, CCR, SCR, DTC, and CTC registers, reset the bq26220 by forcing a power-on-reset and setting the state of the STAT pin as described in Table 11. Table 11. CLR Register CLR BITS 7 6 5 4 3 2 1 (MSB) RSVD 0 (LSB) RSVD RSVD CTC DTC SCR CCR DCR Table 12. CLR Register Definitions RSVD RSVD bits (bits 5, 6 and 7) are reserved for future use and should be written to 0 by the host. CTC CTC bit (bit 4) clears the CTCH and CTCL registers and the STC bit. A 1 clears the corresponding registers and bit. After the registers are cleared, the CTC bit is cleared. This bit is cleared on power-on-reset. DTC DTC bit (bit 3) clears the DTCH and DTCL registers and the STD bit. A 1 clears the corresponding registers and bit. After the registers are cleared, the DTC bit is cleared. This bit is cleared on power-on-reset. SCR SCR bit (bit 2) clears both the SCRH and SCRL registers. Writing a 1 to this bit clears the SCRH and SCRL register. After these registers are cleared, the SCR bit is cleared. This bit is cleared on power-on-reset. CCR CCR bit (bit 1) clears both the CCRH and CCRL registers. Writing a 1 to this bit clears the CCRH and CCRL registers. After these registers are cleared, the CCR bit is cleared. This bit is cleared on power-on-reset. DCR DCR bit (bit 0) clears both the DCRH and DCRL registers. Writing a 1 to this bit clears the DCRH and DCRL registers. After these registers are cleared, the DCR bit is cleared. This bit is cleared on power-on-reset. flash command register (FCMD) The FCMD register (address 0x62) is the flash command register and programs a single flash byte-location, perform flash page erase, transfer RAM to flash and flash to RAM, enter sleep mode, and power-down. These functions are performed by writing the desired command code to the FCMD register. After the bq26220 has finished executing the issued command, the flash command register is cleared. Table 13. FCMD Register Definitions 0x0F Program byte command code. This code ANDs the contents of the FPD register with the contents of flash byte location pointed to by the contents of the FPA register. 0x40 Erase page 0 command code. This code erases all the bytes of flash from address 0x00 to 0x1F. 0x41 Erase page 1 command code. This code erases all the bytes of flash from address 0x20 to 0x3F. 0x42 Erase page 2 command code. This code erases all the bytes of flash from address 0x40 to 0x5F. 0x45 RAM-to-flash transfer code. This code programs the contents of the RAM into Page 0 flash, addresses 0x00 though 0x1F. 0x48 Flash-to-RAM transfer code. This code copies the contents of the page 0 flash into RAM. 0xF6 Power-down code. This code places the bq26220 into the sleep mode when the conditions are met as indicated by the WOE bits in the MODE/WOE register. The part remains in sleep mode until a high-to-low or low-to-high transition occurs on the HDQ pin. www.ti.com 17 SLUS521B − AUGUST 2002 − REVISED FEBRUARY 2004 APPLICATION INFORMATION temperature registers (TMPH, TMPL) The TMPH (address 0x61) and the TMPL registers (address 0x60) reports die temperature in hex format in units of 0.25_K.The temperature is reported as 11 bits of data, using all 8 bits of the TMPL low register and the 3 bits of the TMPH register. The temperature should be read as the concatenation of TMPH [2:0] and TMPL [7:0], 0.25_K/LSB. The 5 MSBs of TMPH, TMPH [7:3], are cleared on POR and are reserved. The 5 bits should also be masked off when reading the temperature, to ensure that incorrect data is not used when calculating the temperature. 18 www.ti.com PACKAGE OPTION ADDENDUM www.ti.com 8-Aug-2014 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Op Temp (°C) Device Marking (4/5) BQ26220PW NRND TSSOP PW 8 100 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR -20 to 70 26220 BQ26220PWG4 NRND TSSOP PW 8 100 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR -20 to 70 26220 BQ26220PWR NRND TSSOP PW 8 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR -20 to 70 26220 BQ26220PWRG4 NRND TSSOP PW 8 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR -20 to 70 26220 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com 8-Aug-2014 Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. 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Addendum-Page 2 PACKAGE MATERIALS INFORMATION www.ti.com 13-Feb-2016 TAPE AND REEL INFORMATION *All dimensions are nominal Device BQ26220PWR Package Package Pins Type Drawing TSSOP PW 8 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 2000 330.0 12.4 Pack Materials-Page 1 7.0 B0 (mm) K0 (mm) P1 (mm) 3.6 1.6 8.0 W Pin1 (mm) Quadrant 12.0 Q1 PACKAGE MATERIALS INFORMATION www.ti.com 13-Feb-2016 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) BQ26220PWR TSSOP PW 8 2000 367.0 367.0 38.0 Pack Materials-Page 2 PACKAGE OUTLINE PW0008A TSSOP - 1.2 mm max height SCALE 2.800 SMALL OUTLINE PACKAGE C 6.6 TYP 6.2 SEATING PLANE PIN 1 ID AREA A 0.1 C 6X 0.65 8 1 3.1 2.9 NOTE 3 2X 1.95 4 5 B 4.5 4.3 NOTE 4 SEE DETAIL A 8X 0.30 0.19 0.1 C A 1.2 MAX B (0.15) TYP 0.25 GAGE PLANE 0 -8 0.15 0.05 0.75 0.50 DETAIL A TYPICAL 4221848/A 02/2015 NOTES: 1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing per ASME Y14.5M. 2. This drawing is subject to change without notice. 3. This dimension does not include mold flash, protrusions, or gate burrs. Mold flash, protrusions, or gate burrs shall not exceed 0.15 mm per side. 4. This dimension does not include interlead flash. Interlead flash shall not exceed 0.25 mm per side. 5. Reference JEDEC registration MO-153, variation AA. www.ti.com EXAMPLE BOARD LAYOUT PW0008A TSSOP - 1.2 mm max height SMALL OUTLINE PACKAGE 8X (1.5) 8X (0.45) SYMM 1 8 (R0.05) TYP SYMM 6X (0.65) 5 4 (5.8) LAND PATTERN EXAMPLE SCALE:10X SOLDER MASK OPENING METAL SOLDER MASK OPENING METAL UNDER SOLDER MASK 0.05 MAX ALL AROUND 0.05 MIN ALL AROUND SOLDER MASK DEFINED NON SOLDER MASK DEFINED SOLDER MASK DETAILS NOT TO SCALE 4221848/A 02/2015 NOTES: (continued) 6. Publication IPC-7351 may have alternate designs. 7. Solder mask tolerances between and around signal pads can vary based on board fabrication site. www.ti.com EXAMPLE STENCIL DESIGN PW0008A TSSOP - 1.2 mm max height SMALL OUTLINE PACKAGE 8X (1.5) 8X (0.45) SYMM (R0.05) TYP 1 8 SYMM 6X (0.65) 5 4 (5.8) SOLDER PASTE EXAMPLE BASED ON 0.125 mm THICK STENCIL SCALE:10X 4221848/A 02/2015 NOTES: (continued) 8. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate design recommendations. 9. Board assembly site may have different recommendations for stencil design. www.ti.com IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. 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