19-4584; Rev 0; 5/09 12-Channel, High-Voltage Battery-Pack Fault Monitor The MAX11080 is a battery-pack fault-monitor IC capable of monitoring up to 12 lithium-ion (Li+) battery cells. This device is designed to provide an overvoltage or undervoltage fault indication when any of the cells cross the user-selectable threshold for longer than the set program-delay interval. The overvoltage levels are pin selectable from +3.3V to +4.8V in 100mV increments, and have a guaranteed accuracy of 25mV over the entire temperature range. The undervoltage level is also user selectable from +1.6V to +2.8V in 200mV increments. These levels are guaranteed to 100mV over the entire temperature range. Undervoltage detection can be disabled as one of the user-configuration options. The MAX11080 has a built-in level-shifter that allows up to 31 MAX11080 devices to be connected in a daisychain fashion to reduce the number of interface signals needed for large stacks of series batteries. Each cell is monitored differentially and compared to the overvoltage and undervoltage thresholds. When any of the cells exceed this threshold for longer than the set program delay interval, the MAX11080 inhibits the heartbeat signal from being passed down the daisy chain. Built-in comparator hysteresis prevents threshold chattering. The MAX11080 is designed to be the perfect complement to the MAX11068 high-voltage measurement IC for redundant fault-monitoring applications. This device is offered in a 9.7mm x 4.4mm, 38-pin TSSOP package with 0.5mm pin spacing. The package is lead-free and RoHS compliant with an extended operating temperature range of -40C to +105C. Applications High-Voltage, Multicell-Series-Stacked Battery Systems Electric Vehicles Features o Up to 12-Cell Li+ Battery Voltage Fault Detection o Operation from 6.0V to 72V o Pin-Selectable Overvoltage Threshold from +3.3V to +4.8V in 100mV Increments 25mV Overvoltage-Detection Accuracy o Pin-Selectable Undervoltage Threshold from +1.6V to +2.8V in 200mV Increments 100mV Undervoltage-Detection Accuracy o 300mV Over/Undervoltage-Threshold Detection Hysteresis o Programmable Delay Time of Alarm Detection from 3.0ms to 3.32s with an External Capacitor o Daisy-Chained Alarm and Shutdown Functions with Heartbeat Status Signal Up to 31 Devices Can Be Connected o Ultra-Low-Power Dissipation Operating-Mode Current Drain: 80A Shutdown-Mode Current: 2A o Wide Operating Temperature Range from -40C to +105C (AEC-Q100 Type 2) o 9.7mm x 4.4mm, 38-Pin TSSOP Package o Lead(Pb) Free and RoHS Compliant Ordering Information PART MAX11080GUU+ TEMP RANGE -40C to +105C PIN-PACKAGE 38 TSSOP MAX11080GUU/V+ -40C to +105C 38 TSSOP +Denotes a lead(Pb)-free/RoHS-compliant package. /V denotes an automotive qualified part. Hybrid Electric Vehicles Electric Bikes Pin Configuration appears at end of data sheet. High-Power Battery Backup Solar Cell Battery Backup Super-Cap Battery Backup ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. 1 MAX11080 General Description MAX11080 12-Channel, High-Voltage Battery-Pack Fault Monitor ABSOLUTE MAXIMUM RATINGS ESD Rating C_, REF, VAA, VDDU GNDU, DCIN, SHDN, CP+, CP-, HV, OVSEL_, UVSEL_, TOPSEL, ALRMU, ALRML, AGND, CD ..............................2kV (Human Body Model, Note 3) Continuous Power Dissipation (TA = +70C) 38-Pin TSSOP (derating 15.9mW/C above +70C) .........................1095.9mW Operating Temperature Range .........................-40C to +105C Storage Temperature Range .............................-55C to +150C Junction Temperature (continuous) .................................+150C Lead Temperature (soldering, 10s) .................................+300C HV, VDDU, GNDU, DCIN to AGND.........................-0.3V to +80V HV to DCIN and C12 ................................................-0.3V to +6V C2-C12 to AGND ....................................-0.3V to (VDCIN + 0.6V) Cn+1 to Cn, where n = 2 to 12...............................-0.3V to +80V C1 to C0 ...................................................-0.3V to +20V (Note 1) C1 to AGND ..............................-0.3V to (VDCIN + 0.6V) (Note 2) C0 to AGND...........................................................-0.3V to +0.9V SHDN, VAA to AGND ................................................-0.3V to +4V VDDU to GNDU .........................................................-0.3V to +6V OVSEL_, UVSEL_, TOPSEL to AGND ......-0.3V to (+VAA + 0.3V) CD, ALRML to AGND ...............................-0.3V to (+VAA + 0.3V) ALRMU to GNDU ...................................-0.3V to (+VDDU + 0.3V) CP+ to AGND ...........................(GNDU - 0.3V) to (VDDU + 0.3V) CP- to AGND...........................................-0.3V to (GNDU + 0.3V) CP- to VDDU .......................................................................+0.3V Note 1: The C1 to C0 differential input path is tolerant to 80V as long as the SHDN pin is deasserted. Note 2: The C1 input is tolerant to a maximum VDCIN + 0.6V. If SHDN is asserted, 20V is the maximum rating. Note 3: Human Body Model to Specification MIL-STD-883 Method 3015.7. Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (TA = TMIN to TMAX, unless otherwise noted. VDCIN = VGNDu = +6.0V to +72V, typical values are at TA = +25C, unless otherwise specified from -40C to +105C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 72 V +1 A C_ INPUTS Common-Mode Input Range VCXIN Any two inputs Cn to Cn+1 for full threshold accuracy (Note 4) 1.5 Input Current ICXIN VCELL = 3.0V -1 Overvoltage Threshold VOV +3.3 5 Overvoltage-Threshold Accuracy Undervoltage Threshold VUV +1.6 Undervoltage-Threshold Accuracy Comparator Hysteresis 0.05 20 VHYS +4.8 V 25 mV +2.8 V 100 mV 300 mV CD PIN CD Current ICD VCD = 0.4V CD Trip Voltage VCD Internal at comparator 1.23 V Excluding CDLY variation 20 % Delay-Time Accuracy 4.35 6.1 7.65 A STATUS/CONTROL PORT Shutdown Disable (SHDN High Voltage) SHDN/VIH Shutdown Asserted (SHDN Low Voltage) SHDN/VIL 2 2.1 _______________________________________________________________________________________ V 0.6 V 12-Channel, High-Voltage Battery-Pack Fault Monitor (TA = TMIN to TMAX, unless otherwise noted. VDCIN = VGNDu = +6.0V to +72V, typical values are at TA = +25C, unless otherwise specified from -40C to +105C.) PARAMETER SYMBOL CONDITIONS MIN VDDU Output High VDDU VOH Output voltage of VDDU after the 20k/200k resistor-divider to SHDN VDDU Output Low VDDU VOL Output voltage of VDDU after the 20k/200k resistor-divider for SHDN ALRML Output-Voltage High ALRML VOH ISOURCE = 150A ALRML Output-Voltage Low ALRML VOL ISINK = 150A ALRMU Input-Voltage High ALRMU VIH Daisy-chained ALRMU signal as coupled through a 3.3nF high-voltage capacitor and a 150k resistor as referred to GNDU ALRMU Input-Voltage Low ALRMU VIL Daisy-chained ALRMU signal as coupled through a 3.3nF high-voltage capacitor and a 150k resistor as referred to GNDU Alarm Voltage Output "Heartbeat" Frequency ALRML fOUT Heartbeat clock rate with no alarm condition 4032 Heartbeat clock rate with no alarm condition Alarm Voltage Output Duty Cycle TYP MAX GNDU + 2.4 UNITS V GNDU + 0.3 2.4 V V 0.6 GNDU + 2.1 V V GNDU + 0.9 V 4157 Hz 49.0 51.0 % 6 72 V 4096 LINEAR REGULATOR (VAA) Input Voltage Range Output Voltage VDCIN VAAOUT Short-Circuit Current Power-On-Reset Trip Level (Note 4) 3.0 3.3 VAARESET Falling VAA 2.8 VAAVALID Rising VAA 3.0 VAAHYS Thermal Shutdown 6V < VDCIN < 72V, ILOAD = 0 IAASHORTCIRCUIT VAA = 0, 6V < VDCIN < 36V TSHUT Hysteresis on rising VAA Rising temperature 3.6 V 50 mA V 37 mV +145 C POWER-SUPPLY REQUIREMENTS (DCIN) Current Consumption IDCIN IGNDu Operating Mode Operating mode, SHDN = 1, 12 battery cells, alarm inactive, VDCIN = VGNDU = 36V 35 Shutdown mode, SHDN = 0, 12 battery cells, VDCIN = VGNDU = 36V 1.3 2 SHDN = 1, battery cells, alarm inactive, VDCIN = VGNDU = 36V 35 40 40 A A LOGIC INPUTS AND OUTPUTS Threshold Setting VIH UVSEL0/UVSEL1/UVSEL2, TOPSEL VIL OVSELO/OVSEL1/OVSEL2/OVSEL3 VAA 0.1 V 0.1 Note 4: Guaranteed by design and not production tested. _______________________________________________________________________________________ 3 MAX11080 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (TA = +25C, unless otherwise noted.) MAX 1.62 35 6.03 MAX11080 toc02 1.6V SET POINT MAX11080 toc01 30 VCD = 0.4V 6.02 1.60 MEAN 1.59 1.58 1.57 CD CURRENT (A) 25 1.61 DEVICE COUNT 20 15 6.00 5.99 10 5.98 5 5.97 1.55 5.96 0 -20 0 40 20 60 80 100 5.8 6.0 6.4 6.2 -40 6.6 40 20 60 80 100 TEMPERATURE (C) DCIN SUPPLY CURRENT vs. VDCIN GNDU SUPPLY CURRENT vs. GNDU VOLTAGE OVERVOLTAGE CLEAR THRESHOLD vs. TEMPERATURE 55 TA = +105C OVERVOLTAGE CLEAR THRESHOLD (V) 50 4.54 45 TA = +105C 40 TA = +25C 35 TA = -40C 30 25 30 TA = +25C 20 TA = -40C 20 15 10 20 30 40 50 60 70 80 10 20 30 40 50 60 70 4.49 MIN 4.48 80 -40 -20 0 20 MEAN 4.798 MIN 4.794 4.792 1.94 1.6V SET POINT 1.92 MAX 1.90 1.88 MEAN 1.86 MIN 1.84 1.82 -40 -20 0 20 40 60 TEMPERATURE (C) 80 40 100 60 TEMPERATURE (C) UNDERVOLTAGE CLEAR THRESHOLD (V) MAX 4.802 MAX11080 toc07 4.8V SET POINT OVERVOLTAGE SET THRESHOLD (V) 4.50 UNDERVOLTAGE CLEAR THRESHOLD vs. TEMPERATURE 4.806 4.796 MEAN 4.51 VGNDU (V) OVERVOLTAGE SET THRESHOLD vs. TEMPERATURE 4.800 4.52 4.47 0 VDCIN (V) 4.804 4.8V SET POINT MAX 4.53 -40 -20 0 20 40 60 80 100 TEMPERATURE (C) _______________________________________________________________________________________ MAX11080 toc08 IGNDU (A) 50 0 0 CD PIN CURRENT (A) 60 40 -20 TEMPERATURE (C) 4.8V OVERVOLTAGE THRESHOLD VCELL = VDCIN/12 70 5.6 5.4 MAX11080 toc04 -40 80 100 MAX11080 toc06 1.56 4 6.01 MIN MAX11080 toc05 UNDERVOLTAGE SET THRESHOLD (V) 1.64 1.63 CD CHARGING CURRENT vs. TEMPERATURE CD CURRENT DISTRIBUTION MAX11080 toc03 UNDERVOLTAGE SET THRESHOLD vs. TEMPERATURE IDCIN (A) MAX11080 12-Channel, High-Voltage Battery-Pack Fault Monitor 12-Channel, High-Voltage Battery-Pack Fault Monitor PIN NAME 1 DCIN DC Power-Supply Input. DCIN supplies the internal 3.3V regulator. This pin should be connected as shown in the application diagrams. 2 HV High-Voltage Bias. HV is biased by the output of the charge pump to provide a DC supply above the DCIN level. It is used internally to bias the cell-comparator circuitry. Bypass to DCIN with a 1F capacitor. 3, 33 N.C. No Connection 4 C12 Cell 12 Plus Connection. Top of battery module stack. 5 C11 Cell 12 Minus Connection and Cell 11 Plus Connection 6 C10 Cell 11 Minus Connection and Cell 10 Plus Connection 7 C9 Cell 10 Minus Connection and Cell 9 Plus Connection 8 C8 Cell 9 Minus Connection and Cell 8 Plus Connection 9 C7 Cell 8 Minus Connection and Cell 7 Plus Connection 10 C6 Cell 7 Minus Connection and Cell 6 Plus Connection 11 C5 Cell 6 Minus Connection and Cell 5 Plus Connection 12 C4 Cell 5 Minus Connection and Cell 4 Plus Connection 13 C3 Cell 4 Minus Connection and Cell 3 Plus Connection 14 C2 Cell 3 Minus Connection and Cell 2 Plus Connection 15 C1 Cell 2 Minus Connection and Cell 1 Plus Connection 16 C0 Cell 1 Minus Connection 17 UVSEL0 18 UVSEL1 19 UVSEL2 20 OVSEL0 21 OVSEL1 22 OVSEL2 23 OVSEL3 24 VAA 25, 29, 30, 32 AGND Analog Ground. Should be connected to the negative terminal of cell 1. SHDN Active-Low Shutdown Input. This pin completely shuts down the MAX11080 internal regulator and oscillators when the pin is less than 0.6V as referenced to AGND. The host controller should drive SHDN for the first pack. SHDN for daisy-chained modules should be connected to the lower neighboring module's VDDU through a 20k series resistor. 27 ALRML Lower Port Alarm Output. This output is an alarm indicator for overvoltage, undervoltage, and setup faults. The alarm signal is daisy chained and driven from the highest module down to the lowest. The alarm output is nominally a clocked "heartbeat" signal that provides a 4kHz clock when no alarm is present. The ALRML can also be configured as level signal and set to "low" for no alarm and "high" for alarm state. See the TOPSEL Function section for details. This signal swings between VAA and AGND, and is active high in the alarm state. 28 CD 26 FUNCTION Undervoltage Threshold Select 2 to 0. Used to select one of eight undervoltage alarm threshold settings. The parts have internal pulldown; these pins should only be tied to VAA or AGND to set the logic state. Overvoltage Threshold Select 3 to 0. Used to select one of 16 overvoltage alarm threshold settings. The parts have internal pulldown; these pins should only be tied to VAA or AGND to set the logic state. +3.3V Analog Supply Output. Bypass with a 1F capacitor to AGND. Programmable Delay Time. Connect a capacitor from this pin to AGND to set the hold time required for a fault condition before the alarm is set. The capacitor should be a ceramic capacitor in the 15nF to 16.5F range. _______________________________________________________________________________________ 5 MAX11080 Pin Description MAX11080 12-Channel, High-Voltage Battery-Pack Fault Monitor Pin Description (continued) 6 PIN NAME FUNCTION 31 TOPSEL Input to Indicate Topmost Device in the Daisy Chain. This pin should be connected to AGND for all devices except the topmost. For the top device, this pin should be connected to VAA. 34 ALRMU Upper Port Alarm Input. This input receives the ALRML output signal from an upper neighboring module. It swings between VDDU and GNDU. 35 GNDU Level-Shifted Upper Port Ground. Upper port-supply return and supply input for the charge pump and HV supplies. This pin should be connected to the DCIN takeoff point on the battery stack as shown in the application diagrams. 36 VDDU Level-Shifted Upper Port Supply. Upper port-supply output for the daisy-chained bus. This is a regulated output voltage from the internal charge pump that is level-shifted above the DCIN pin voltage level. It should be bypassed with a 1F capacitor to GNDU. 37, 38 CP-, CP+ Charge-Pump Capacitor. Negative/positive input for the internal charge pump. Connect a 0.01F highvoltage capacitor between CP+ and CP-. _______________________________________________________________________________________ 12-Channel, High-Voltage Battery-Pack Fault Monitor MAX11080 HV DCIN C12 LDO REGULATOR CELL COMPARATORS VAA C11 UPPER PORT CELL COMPARATORS C10 VDDU ALRMU GNDU CELL COMPARATORS C9 CELL COMPARATORS LEVEL SHIFT C8 CP+ CP- CELL COMPARATORS C7 CELL COMPARATORS C6 FAULT FAULT CELL COMPARATORS LOWER PORT ALRML SHDN C5 CELL COMPARATORS OVSEL3 C4 OVSEL2 CELL COMPARATORS C3 CELL COMPARATORS OVSEL1 FAULT-STATE MACHINE AND CONTROL LOGIC OVSEL0 TOPSEL C2 CELL COMPARATORS UVSEL2 C1 UVSEL1 CELL COMPARATORS UVSEL0 C0 MAX11080 AGND CD Figure 1. Functional Diagram _______________________________________________________________________________________ 7 MAX11080 12-Channel, High-Voltage Battery-Pack Fault Monitor MODULE N+1 CELL STACK MODULE N+1 GND REFERENCE FUSE MODULE-(N+1) RDCIN 5k BUS BAR MODULE+(N) CDCIN 0.1F 80V CHV 1F 6V SMCJ70 HV R13 DPROT CELL 12 R12 VDDU C12 GNDU C11 CELL 11 R11 R10 C11 CELL 9 C10 R9 C9 R8 C8 MAX11080 C7 CELL 7 R7 R6 R5 CP 0.01F 100V CA 1F 6V ALRML SHDN RSHD 200k C5 C4 CELL 4 R4 C4 R3 OVSEL2 C3 OVSEL1 C2 CELL 2 R2 OVSEL0 C2 UVSEL2 C1 CELL 1 UVSEL1 UVSEL0 C1 C0 MODULE-(N) TOPSEL AGND LOCAL GROUND BUS BAR VAA OVSEL3 C3 CELL 3 ISOLATOR AND CONTROL INTERFACE RSHD2 20k C6 C5 CELL 5 GNDU SEE TEXT FOR GNDU CONNECTION OPTIONS C7 C6 CELL 6 GNDU MODULE N+1 C3DC 3.3nF 630V GNDU CP+ CPVAA C8 CELL 8 R1DC 150k ALRML GNDU C9 5.6V ALRMU C10 CELL 10 SHDN CDD 1F 6V DCIN C12 DAISY-CHAIN BUS TO UPPER MODULES R2DC 20k CD CDLY 15nF TO 16.5F CERAMIC CAP R2-R13 = 10k C1-C12 = 0.1F/80V MODULE N-1 CELL STACK MODULE N-1 GNDU TAKEOFF Figure 2. Application Circuit Diagram for a 12-Cell System 8 _______________________________________________________________________________________ JUMPER BANK 12-Channel, High-Voltage Battery-Pack Fault Monitor MAX11080 MODULE N+1 CELL STACK MODULE N+1 GND REFERENCE FUSE MODULE-(N+1) RDCIN 5k CDCIN 0.1F 80V BUS BAR MODULE+(N) CHV 1F 6V SMCJ70 HV R11 DPROT CELL 10 VDDU C10 GNDU C11 SHDN CDD 1F 6V DCIN C12 DAISY-CHAIN BUS TO UPPER MODULES R2DC 20k 5.6V R1DC 150k GNDU MODULE N+1 C3DC 3.3nF 630V ALRMU ALRML GNDU GNDU C10 R10 C9 CELL 9 R9 C9 R8 C8 MAX11080 CPVAA C8 CELL 8 GNDU CP+ C7 CELL 7 R7 R6 ALRML R5 SHDN RSHD 200k C5 C4 CELL 4 R4 C4 R3 OVSEL2 C3 OVSEL1 C2 CELL 2 R2 OVSEL0 C2 UVSEL2 C1 CELL 1 UVSEL0 C0 TOPSEL AGND LOCAL GROUND BUS BAR JUMPER BANK UVSEL1 C1 MODULE-(N) VAA OVSEL3 C3 CELL 3 ISOLATOR AND CONTROL INTERFACE RSHD2 20k C6 C5 CELL 5 CA 1F 6V C7 C6 CELL 6 CP 0.01F 100V CD CDLY 15nF TO 16.5F CERAMIC CAP R2-R11 = 10k C1-C10 = 0.1F/80V MODULE N-1 CELL STACK MODULE N-1 GNDU TAKEOFF Figure 3. Application Circuit Diagram for a 10-Cell System _______________________________________________________________________________________ 9 MAX11080 12-Channel, High-Voltage Battery-Pack Fault Monitor MODULE N+1 CELL STACK MODULE N+1 GND REFERENCE FUSE MODULE-(N+1) RDCIN 5k BUS BAR MODULE+(N) CDCIN 0.1F 80V CHV 1F 6V SMCJ70 HV R9 DPROT CELL 8 VDDU C8 GNDU C11 SHDN CDD 1F 6V DCIN C12 DAISY-CHAIN BUS TO UPPER MODULES R2DC 20k 5.6V R1DC 150k GNDU MODULE N+1 C3DC 3.3nF 630V ALRMU ALRML GNDU GNDU C10 C9 MAX11080 GNDU CP+ CPVAA C8 R8 C7 CELL 7 R7 R6 ALRML R5 SHDN RSHD 200k C5 C4 CELL 4 R4 C4 R3 OVSEL2 C3 OVSEL1 C2 CELL 2 R2 OVSEL0 C2 UVSEL2 C1 CELL 1 UVSEL1 UVSEL0 C1 C0 MODULE-(N) TOPSEL AGND LOCAL GROUND BUS BAR VAA OVSEL3 C3 CELL 3 ISOLATOR AND CONTROL INTERFACE RSHD2 20k C6 C5 CELL 5 CA 1F 6V C7 C6 CELL 6 CP 0.01F 100V CD CDLY 15nF TO 16.5F CERAMIC CAP R2-R9 = 10k C1-C8 = 0.1F/80V MODULE N-1 CELL STACK MODULE N-1 GNDU TAKEOFF Figure 4. Application Circuit Diagram for an 8-Cell System 10 ______________________________________________________________________________________ JUMPER BANK MODULE N-1 CELL STACK BUS BAR MODULE-(N) CELL 1 CELL 2 CELL 3 CELL 4 CELL 5 CELL 6 CELL 7 CELL 8 CELL 9 CELL 10 CELL 11 CELL 12 MODULE+(N) BUS BAR CDCIN1 D1 FUSE C1Q750 (1206) R26 BATTERY CONNECTOR DCIN DCIN HV R25 C24 GNDU R24 C23 CP+ C9 C10 R22 C21 LOCAL GROUND R23 C22 R21 C20 R20 C19 R19 C18 MAX11080 R18 C17 R17 C16 R16 C15 R15 C14 C13 SHDN C2 VDDU C11 VAA AGND R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 REFER TO EACH DEVICE'S APPLICATION REFERENCE CIRCUITS FOR COMPONENTS AND VALUES NOT SHOWN ON THIS SIMPLIFIED SYSTEM-LEVEL SCHEMATIC. DPROT1 SMCJ70 D2 RDCIN2 CPC8 MODULE-(N+1) ALRML C1 DPROT2 SMCJ70 C7 CDCIN2 C5 ALRMU C12 UVSEL2 UVSEL1 UVSEL0 C4 OVSEL3 OVSEL2 OVSEL1 OVSEL0 C6 TOPSEL C3 CD C0 MODULE N+1 GND REFERENCE C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 AGND REF VDDU GPIO0 GPIO1 GPIO2 GNDL SHDN ALRML SDAL SCLL VDDL VAA CP- CP+ GNDU SDAU SCLU ALRMU DCIN ISOLATOR AND CONTROL INTERFACE FOR FIRST MODULE MAX11068 HV DCIN AUXIN2 AUXIN1 THRM C0 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 GPIO SDAL SCLL ALRML (MAX11068) ALRML (MAX11080) SHDN MAX11080 MODULE N+1 CELL STACK 12-Channel, High-Voltage Battery-Pack Fault Monitor Figure 5. Battery Module System with Redundant Fault-Detection Application Schematic ______________________________________________________________________________________ 11 MAX11080 12-Channel, High-Voltage Battery-Pack Fault Monitor HV VDDU 6V DCIN CP+ 6V ALRMU 80V C12 80V GNDU 80V CPC1 TO C11 VAA ALRML SHDN ESD DIODES CD MAX11080 TOPSEL 4V 4V 6V OVSEL0/1/2/3 C0 UVSEL0/1/2 AGND Figure 6. ESD Diode Diagram Detailed Description Figure 1 shows the functional diagram; Figure 2 shows the application circuit diagram for a 12-cell system while Figure 3 shows the application circuit design for a 10-cell system and Figure 4 for an 8-cell system. Figure 5 is the application schematic for the battery module system with redundant fault detection. Architectural Overview The MAX11080 is a battery-pack fault-monitor IC capable of monitoring up to 12 Li+ battery cells. This device is designed to provide an overvoltage or undervoltage alarm indicator when any of the cells cross the userselectable threshold for longer than the configured decision delay interval. The MAX11080 also incorporates a daisy-chain bus for use in high-voltage stackedbattery operation. The daisy-chain bus relays shutdown 12 and alarm communication across up to 31 stacked modules without the need for isolation between each module. This results in a simplified system with reduced cost. The MAX11080 is ideal as an ultra-low-power, redundant cell fault monitor that is the perfect complement to the MAX11068 high-voltage battery measurement IC. Both ICs in concert form a powerful Li+ battery system monitor with redundant overvoltage and undervoltage fault detection. Overvoltage and Undervoltage Fault Detection Figure 7 summarizes the fault-detection mechanism for a set of differential cell inputs in the MAX11080. First, the differential cell inputs are attenuated by a factor of four while being level-shifted and converted to a single-ended voltage referenced to AGND. The ground- ______________________________________________________________________________________ 12-Channel, High-Voltage Battery-Pack Fault Monitor CD pin. If the voltage at the CD pin reaches VCD, the ALRML line is set to VAA (+2.4V minimum as referred to AGND). Normally, the ALRML line is a heartbeat signal with pulses occurring every 250s. If all cell voltages transition from out-of-range to in-range before the voltage at pin CD reaches VCD, an internal switch clamps the CD pin to GND. This action discharges CDLY and, because the delay had not yet expired, no alarm occurs. Discharging CDLY ensures that the full delay time occurs for the next overvoltage or undervoltage event. Figure 8 summarizes the CDLY circuit. VOV/4 VCELL/(4 x RSHIFT) 75mV HYSTERESIS HV CELL OUT-OF-RANGE CN+1 + RIN* 40M TYP VCELL RSHIFT + VCELL/4 75mV HYSTERESIS - CN OUT-OF-RANGE 11 AGND CELLS 2-12 VUV/4 + VCELL 6M TYP 2M TYP UNDERVOLTAGE COMPARATOR ENABLE VCELL/4 VSC/4 CELL 1 SHORT-CIRCUIT DETECTOR Figure 7. Cell Differential Input and Comparator Block Diagram VAA 6k CD ICD 6.1A OUT-OF-RANGE ALARM CELL OUT-OF-RANGE 1 TO 12 11 VCD THRESHOLD CDLY Figure 8. CDLY Circuit Block Diagram ______________________________________________________________________________________ 13 MAX11080 referenced voltage is then connected to a set of overvoltage and undervoltage comparators. The threshold references for the comparators are set by the UVSEL_ and OVSEL_ input pins. When one of the cell voltages exceeds VOV or is below VUV when VUV is enabled, the internal cell out-of-range signal for the given cell is set and logically ORed with the same signal for the other cell positions to create an overall out-of-range signal. When any cells are out-of-range as indicated by the internal out-of-range signal, an internal current source begins to charge the capacitor CDLY connected to the MAX11080 12-Channel, High-Voltage Battery-Pack Fault Monitor Once the ALRML pin is forced high due to an alarm (+2.4V minimum as referred to AGND), it transitions back to a heartbeat signal only after all battery cells meet the following condition: (VOV - VHYS) > VCELL(ALL) > (VUV + VHYS) The effective ICD value of the current source is 6.1A typical and the threshold voltage, VCD, is 1.23V typical. The VCD threshold is specified at an internal node prior to the resistor in series with the CD pin as shown in Figure 8. The threshold voltage seen at the pin is approximately 1.18V due to the drop associated with the typical ICD value and the 6k resistor. The MAX11080 can operate with capacitor values from 15nF (3.0ms) to 16.5F (3.32s). Each capacitor should have a voltage tolerance of 5V minimum. Examples of cell-voltage readings and their effect on the alarm status are shown in Figures 9 and 10 for single- and multiple-cell systems. In the case where an upper module is forwarding an active alarm condition down the daisy chain, that condition continues to be propagated toward the host regardless of the alarm state of any lower module. Furthermore, to circumvent the possibility of a short-circuited capacitor connected to CD preempting the fault-time validation process, a redundant built-in delay of 4s nominal is asserted as a backup. If the VCD threshold is not reached within 4s of an out-of-range event, the alarm becomes active. Cell-Voltage Threshold Selection The overvoltage and undervoltage threshold selection is configured through the OVSEL_ and UVSEL_ inputs. The overvoltage selection can be configured from 3.3V to 4.8V in 100mV increments. The undervoltage threshold can be configured from 1.6V to 2.8V in 200mV increments. The undervoltage detection can also be disabled. See Tables 1 and 2 for the proper configuration settings. Immunity to unintended changes in the threshold voltage setting (due to accidental pin-to-pin short circuits, for example) is provided. The customer-programmed selection is sensed and stored at power-up and any subsequent change to the input pin status is ignored. Programmable Delay Time The alarm trigger delay time is calculated according to the following equations: tDLY = (VCD x CDLY)/ICD CDLY = (tDLY x ICD)/VCD Table 1. Overvoltage Threshold Selection THRESHOLD (V) 14 OVERVOLTAGE SELECTION OVSEL3 OVSEL2 OVSEL1 OVSEL0 3.3 0 0 0 0 3.4 0 0 0 1 3.5 0 0 1 0 3.6 0 0 1 1 3.7 0 1 0 0 3.8 0 1 0 1 3.9 0 1 1 0 4.0 0 1 1 1 4.1 1 0 0 0 4.2 1 0 0 1 4.3 1 0 1 0 4.4 1 0 1 1 4.5 1 1 0 0 4.6 1 1 0 1 4.7 1 1 1 0 4.8 1 1 1 1 ______________________________________________________________________________________ 12-Channel, High-Voltage Battery-Pack Fault Monitor MAX11080 VOV VOV - VHYS ANY CELL CELL VOLTAGE VCD CD ALRML Figure 9. Single-Cell Overvoltage Detection Example VOV VOV - VHYS CELL 12 CELL 11 CELL VOLTAGE CELL N CELL 1 VCD CD ALRML Figure 10. Multiple-Cell Overvoltage Detection Example ______________________________________________________________________________________ 15 MAX11080 12-Channel, High-Voltage Battery-Pack Fault Monitor Table 2. Undervoltage Threshold Selection UNDERVOLTAGE SELECTION THRESHOLD (V) UVSEL2 UVSEL1 UVSEL0 Disabled 0 0 0 1.6 0 0 1 1.8 0 1 0 2.0 0 1 1 2.2 1 0 0 2.4 1 0 1 2.6 1 1 0 2.8 1 1 1 Internal Linear Regulator The MAX11080 has an internal linear regulator for generating the internal supply from DCIN (Figure 11). The regulator can accept a supply voltage on the DCIN pin from +6.0V to +72V, which it regulates to 3.3V to run the voltage-detection system, control logic, and lowside alarm-pulse interface. When the SHDN pin is not active and a sufficient voltage is applied to DCIN, the output of the regulator becomes active. The regulator is paired with a power-on-reset (POR) circuit that senses DCIN +6.0V TO +72V LINEAR REGULATOR its output voltage and holds the MAX11080 in a reset state until the internal supply has reached a sustainable threshold of +3.0V (5%). The internal comparators have built-in hysteresis that can reject noise on the supply line. Because secondary metal batteries are never fully discharged to 0V, the MAX11080 is designed for a hot-swap insertion of the battery cells. Once the POR threshold is reached, approximately 1ms later the internal reset signal disables, the internal oscillator starts, and the charge pump begins operating. The charge INTERNAL +3.3V VAA SHDN GNDU REGULATOR ENABLE CHARGE PUMP DIE OVERTEMPERATURE DETECT BANDGAP REFERENCE VDDU CHARGE-PUMP ENABLE 35mV HYSTERESIS +3.3V TO GNDU INTERNAL POR POR THRESHOLD +3.0V 5% POR COMPARATOR Figure 11. Internal Linear Regulator Block Diagram 16 ______________________________________________________________________________________ 12-Channel, High-Voltage Battery-Pack Fault Monitor racy and full operation of the MAX11080 are not guaranteed until a minimum of 6.0V is applied to the DCIN pin. The linear regulator also incorporates a thermal shutdown feature. If the MAX11080 die temperature rises above +145C, the device shuts down. After a thermal shutdown, the die temperature must cool 15C below the shutdown temperature before the device restarts. Figure 12 shows the linear regulator power-up sequence and Figure 13 shows the low DCIN POR event. POR ACTIVE FAULT THRESHOLDS READ VOLTAGE APPLIED TO DCIN SHDN ACTIVE POR INACTIVE 16kHz OSCILLATOR ENABLED FALLING DCIN VOLTAGE CHECK SHDN CHARGE-PUMP ENABLED VAA > 2.8V 3ms DELAY REGULATOR ENABLED CHECK VAA VAA < 3.0V TOP BOARD IDENTIFIED POR ACTIVE OVERVOLTAGE COMPARATOR SELF-TEST CHECK VAA 1ms DELAY NUMBER OF CELLS DETECTED POR CLEARED OSCILLATOR, CHARGE PUMP, DIGITAL LOGIC, AND ALARM PULSE DISABLED MAX11080 FULLY FUNCTIONAL Figure 12. Linear Regulator Power-Up Sequence Figure 13. Low DCIN POR Event ______________________________________________________________________________________ 17 MAX11080 pump reaches regulation in approximately 3ms. The MAX11080 associated with the top module in the battery pack is identified as detailed in the TOPSEL Function section. This is followed by a self-test of the overvoltage comparators and detection of the number of cells connected. At this time in the power-on sequence, the MAX11080 is ready for operation. When the charge pump achieves regulation of 3.3V between VDDU and GNDU, it switches to a standby mode until the voltage drops by about 35mV. The specified accu- MAX11080 12-Channel, High-Voltage Battery-Pack Fault Monitor FUSE TOP OF CELL STACK RDCIN 5k CDCIN 0.1F 80V TO DCIN INPUT PBMB78AT3 SEE THE APPLICATION CIRCUIT DIAGRAMS (FIGURES 15 AND 16) FOR THE PROPER CONNECTION LOCATION. Figure 14. Battery Module Surge and Overvoltage Protection Circuit DCIN and GNDU Supply Connections A surge voltage is produced by the electric motor during regenerative braking conditions. The MAX11080 is designed to tolerate an absolute maximum of 80V under this condition. The MAX11080 should be protected against higher voltages with an external voltage suppressor such as the PBMB78AT3 on the DCIN connection point. This protection circuit also helps to reduce power spikes that can occur during the insertion of the battery cells. During negative voltage excursions, the protection circuit stores enough charge to power the regulator through the transient. Figure 14 shows the clamp configuration to protect the DCIN supply input. The DCIN input contains a comparator circuit to detect an open circuit on this pin for fault-management purposes. Whenever a nominal voltage of two silicon diode drops appears between C12 and DCIN following the power-up sequence, the ALRML output is asserted as a fault indication. This voltage drop must appear for at least the delay time set by CDLY to result in a fault. The voltage drop from C12 to DCIN during normal operation should be kept at no more than 0.5V to prevent erroneous tripping of the DCIN open-circuit comparator under worst-case circumstances (lowest silicon diode forward bias voltage). The diode DDCIN is used to supply the transient current demanded at startup by the decoupling circuit. In parallel with this diode, RDCIN provides the supply path during normal operation. It is selected to be 5k so that the maximum voltage drop between C12 and DCIN is about 0.25V with nominal supply currents. High-power batteries are often used in noisy environments subject to high dV/dt or dI/dt supply noise and EMI noise. For example, the supply noise of a power 18 inverter driving a high horse-power motor produces a large square wave at the battery terminals, even though the battery is also a high-power battery. Typically, the battery dominates the task of absorbing this noise, since it is impractical to put hundreds of farads at the inverter. The MAX11080 is designed with several mechanisms to deal with extremely noisy environments. First, the major power-supply inputs that see the full battery-stack voltage are 80V tolerant. This is high enough to handle the large voltage changes on the battery stack that can occur when the batteries transition between charge and discharge conditions. Next, the linear regulator has high PSRR to produce a clean low-voltage power supply for the internal circuitry. This allows DCIN to be connected directly to the stack voltage. Finally, GND U serves two purposes. It supplies the internal charge pump with its power and acts as the reference ground for the upper alarm communication port. The charge pump creates a secondary low-voltage supply that is referenced to GNDU. Because the level-shifted supply VDDU is referenced to GNDU, the entire upper alarm communication port glides smoothly on GNDU and it is effectively immune to noise on GNDU. The upper alarm signal is internally shifted down to AGND level where it is processed by the digital logic. There are two connection methods that can be used for GNDU depending on application requirements. For the top module in a system, or where GNDU cannot be DC-coupled to the next higher module for other reasons, GNDU should be connected to the same location as DCIN. This connection is valid as long as the voltage difference between the top of Stack(n) and the bottom of Stack(n+1) during worst-case conditions does not exceed the margin of the alarm pin signaling levels. When GNDU is not DC-coupled to the far side of the bus bar, it can be AC-coupled to the far side to maintain alarm communication when the bus bar is open-circuit. In that case, the two sides of the AC-coupling capacitor can be at different DC potentials, but the alarm communication signal continues to be passed across the capacitor connection. It is recommended that an AC- or DC-coupled version of GNDU is paired with the alarm signal through the communication bus wiring, possibly by twisted pair wire, for maximum noise immunity and minimum emissions. The preferred connection to reject noise between modules is when a DC connection can be made from GNDU to AGND of the next module. It is again recommended that the DC-coupled GNDU signal is routed adjacent to the alarm signal as part of the communication bus for maximum noise immunity and minimum emissions. ______________________________________________________________________________________ 12-Channel, High-Voltage Battery-Pack Fault Monitor MAX11080 MODULEN+1 MODULEN+1 DCIN C12 GNDU C12 C11 C11 C2 C2 C1 C1 C0 AGND OPTIONAL TO MAINTAIN ALARM COMMUNICATION MODULEN BUS BAR C0 BUS BAR DCIN GNDU AGND COMMUNICATION BUS MODULEN DCIN DCIN C12 C12 GNDU GNDU C11 C11 C2 C2 C1 C1 C0 C0 AGND AGND Figure 15. GNDU Connection: AC-Coupled to Next Module, DC-Coupled to Present Module Figure 16. GNDU Connection: DC-Coupled with the Communication Bus ______________________________________________________________________________________ 19 MAX11080 12-Channel, High-Voltage Battery-Pack Fault Monitor Shutdown Control The SHDN pin connections of the MAX11080 operate in a manner that allows the shutdown/wake-up command to trickle up through the series of daisy-chained packs. Because the internal linear regulator is powered down during shutdown, the shutdown function must operate when VAA is absent and it, therefore, cannot depend on a Schmitt trigger input. A special low-current, high-voltage circuit is used to detect the state of the SHDN pin. The shutdown pin has a +1.8V minimum threshold for the inactive state. When SHDN > 1.8V, the MAX11080 turns on and begins regulating VDD U and VDD L. If SHDN < 0.6V, the MAX11080 shuts down. For automatic shutdown when the pack is removed from the system, connect a 200k resistor from SHDN to AGND. Once SHDN is driven high, the power-up sequence follows that described for the internal linear regulator. The SHDN signal of the next higher module should be connected to VDDU through a 20k resistor pullup. This connection ensures that the next module in the daisy chain is enabled as VDDU of the lower module powers up. This action propagates up the daisy chain until the last battery module is enabled. The shutdown of a VDD U supply pulls the connected SHDN pin of the upper module toward GNDL and propagates the shutdown signal up the daisy chain. A shutdown signal propagated from the first daisychain device to the last incurs a certain amount of delay. A deasserted shutdown signal is not propagated to the next higher module until the charge pump has regulated the level-shifted upper port supply, VDDU, to a value greater than the SHDN V IH level. This time depends on both the charge-pump capacitor used and the value of the VDDU decoupling capacitor. A typical time delay of 10ms can be expected from the time the SHDN pin reaches the deasserted state until VDD U reaches its full specified value. to leave unused. The example application circuits in this document have chosen to populate the uppermost cell position and group the unused inputs just under this cell. At power-up, the part compares the voltage applied to each cell input with a nominal cell-detection threshold voltage of 0.7V. If the cell voltage is less than the celldetection threshold, undervoltage detection is disabled for that cell input. If the voltage at the input is 0.7V or greater, undervoltage detection is specified by the state of the UVSEL_ inputs. Overvoltage detection is always enabled for all cell-voltage inputs. The cell-connection detection occurs just before the MAX11080 is fully functional as shown in Figure 12 under "Number of Cells Detected." TOPSEL Function The TOPSEL pin is used to indicate to a device whether it is the top device in the daisy-chain stack. The top daisy-chain device is responsible for generating the heartbeat signal at the top of the ALRM_ pin bus. This heartbeat propagates along the chain toward the host. To designate a device as the top device, the TOPSEL pin should be connected to VAA. For all other devices in a daisy chain, this pin should be connected to AGND. The TOPSEL pin has a weak internal pulldown resistor, but this resistor should not be relied upon as the sole means of setting the TOPSEL logic level. The logic level of the TOPSEL pin is not latched internally at startup and is continuously sampled during operation. The ALRMU input should be connected to GNDU for the top module as good design practice to prevent noise pickup even though the input logic level is ignored. For the single device application, the device enters the "level" mode when the TOPSEL is connected to AGND. The ALRML shows the level of AGND for no alarm state and VAA for alarm state. ALRM U has to be tied to GNDU for this mode. The following table summarizes the operation of TOPSEL and ALRML: C1 Input Absolute Maximum Rating The C1 input is limited to VDCIN - 0.6V above AGND or a maximum of 20V if the SHDN pin is asserted. If an application requires that the 20V restriction be removed during active shutdown, then a 4.0V zener diode can be added from VAA to AGND. This protects VAA and allows the C1 input to go to VDCIN - 0.6V regardless of the SHDN state. It also allows the differential C1 to C0 voltage to range from -0.3V to +80V. Cell-Connection Detection An individual MAX11080 can be connected to as many as 12 series-connected cells. To accommodate configurations with fewer cells, unused cell inputs must be shorted together. The designer can choose which cell inputs 20 TOPSEL ALRMU 0 1 ALRML No alarm alarm 0 0 1 X Heartbeat 1 Internal Self-Test The MAX11080 performs an internal self-test during power-up according to the linear regulator power-up flowchart (Figure 12). Each overvoltage comparator is tested for the ability to detect an internally generated overvoltage test condition. This is done by using the ground voltage level as the threshold reference in place of the usual threshold level. Figure 8 shows the connec- ______________________________________________________________________________________ 12-Channel, High-Voltage Battery-Pack Fault Monitor Failure Mode and Effects Analysis High-voltage battery-pack systems can be subjected to severe stresses during in-service fault conditions and could experience similar conditions during the manufacturing and assembly process. The MAX11080 is designed with high regard to these potential states. Open and short circuits at the package level must be readily detected for fault diagnosis and should be tolerated whenever possible. A number of circuits are employed within the MAX11080 specifically to detect such conditions and progress to a known device state. Table 3 summarizes other conditions typical in a normal manufacturing process along with their effect on the MAX11080 device. See Table 4 for the FEMA analysis of the MAX11080. If the cell voltage is within the monitor range, the heartbeatsignal on the ALRML resumes once the fault condition (either open or short) is removed, unless specified. Table 3. System Fault Modes CONDITION EFFECT DESIGN RECOMMENDATION Refer to the pin-level FMEA analysis spreadsheet available from the factory The built-in features of the MAX11080 should ensure low FMEA risk in most cases. Random connection of cells to IC-- no stack load No effect The series resistors on the cell inputs of the MAX11080 as well as the internal design ensure protection against random power supply or ground connections. Random connection of modules-- no stack load No effect Each module is referenced to its neighbor, so no special connection order is necessary. Random connect/disconnect of communication bus--no stack load; AC- or DC-coupled The level-shifted interface design of the Communication from host to the first break MAX11080 ensures that the SHDN, GNDU, in the daisy-chain bus and ALRM_ communication bus can be connected at any time with no load. Random connect/disconnect of communication bus--with stack load; AC- or DC-coupled The level-shifted interface design of the MAX11080 ensures that the SHDN, GNDU, Communication from host to the first break ALRM_ communication bus can be in the daisy-chain bus connected at any time as long as the power bus is properly connected. Connect/disconnect module interconnect (bus bar)--no stack load No effect for DC- or AC-coupled communication bus A break in the power bus does not cause a problem as long as there is no load on the stack. Removal/fault of module interconnect (bus bar)--with stack load No effect for AC-coupled communication bus; device damage for DC-coupled bus An AC-coupled bus with isolation on the SHDN pin or a redundant bus-bar connection should be used to protect against this case. Removal/fault of module interconnect (bus bar)--with stack under charge No effect for AC-coupled communication bus; device damage for DC-coupled bus An AC-coupled bus with isolation on the SHDN pin or a redundant bus-bar connection should be used to protect against this case. PCB or IC package open or short circuit-- no stack load ______________________________________________________________________________________ 21 MAX11080 tion for this test-mode compare level. If all comparators can detect the internally generated overvoltage test event, part operation continues. If any comparator fails to detect the internally generated overvoltage test event, a fault is signaled using the ALRML pin. The device must be power cycled to retest the comparators and attempt to clear this fault condition. MAX11080 12-Channel, High-Voltage Battery-Pack Fault Monitor Table 4. FEMA Analysis (Note 5) PIN NUMBER NAME 1 DCIN 2 HV 3 4 5 6 7 22 N.C. ACTION EFFECT Open (or Disconnected) ALRML goes high (see Note 6). Short to Pin 2 ALRML goes high. Open (or Disconnected) ALRML goes high. Short to Pin 3 No effect. Open (or Disconnected) No effect. Short to Pin 4 No effect. Open (or Disconnected) * If open occurs before power-up, the part works as if C12 does not exist because the internal circuit detects the situation and assumes it is what the application intended to do. The monitoring of C12 to C11 is disabled and is not enabled even if the pin is reconnected. * If open occurs after power-up, it is considered a zero voltage input. ALRML goes high when the undervoltage is enabled. Short to Pin 5 * If short occurs before power-up, the part works as if C12 does not exist because the internal circuit detects the situation and assumes it is what the application intended to do. The monitoring of C12 to C11 is disabled and is not enabled even if the short is removed. * If short occurs after power-up, the situation is treated as a zero voltage input for C12 to C11. ALRML goes high when the undervoltage is enabled. Open (or Disconnected) ALRML goes high because it causes an overvoltage to the affected input pair even if the overvoltage is set to the maximum. Short to Pin 6 * If short occurs before power-up, the part works as if C11 does not exist because the internal circuit detects the situation and assumes it is what the application intended to do. The monitoring of C11 to C10 is disabled and is not enabled even if the short is removed. * If short occurs after power-up, the situation is treated as a zero voltage input for C11 to C10. ALRML goes high when the undervoltage is enabled. Open (or Disconnected) ALRML goes high as it causes an overvoltage to the affected input pair even if the overvoltage is set to the maximum. Short to Pin 7 * If short occurs before power-up, the part works as if C10 does not exist because the internal circuit detects the situation and assumes it is what the application intended to do. The monitoring of C10 to C9 is disabled and is not enabled even if the short is removed. * If short occurs after power-up, the situation is treated as a zero voltage input for C10 to C9. ALRML goes high when the undervoltage is enabled. Open (or Disconnected) ALRML goes high as it causes an overvoltage to the affected input pair even if the overvoltage is set to the maximum. Short to Pin 8 * If short occurs before power-up, the part works as if C9 does not exist because the internal circuit detects the situation and assumes it is what the application intended to do. The monitoring of C9 to C8 is disabled and is not enabled even if the short is removed. * If short occurs after power-up, the situation is treated as a zero voltage input for C9 to C8. ALRML goes high when the undervoltage is enabled. C12 C11 C10 C9 ______________________________________________________________________________________ 12-Channel, High-Voltage Battery-Pack Fault Monitor PIN NUMBER 8 9 10 11 12 NAME ACTION EFFECT Open (or Disconnected) ALRML goes high as it causes an overvoltage to the affected input pair even if the overvoltage is set to the maximum. Short to Pin 9 * If short occurs before power-up, the part works as if C8 does not exist because the internal circuit detects the situation and assumes it is what the application intended to do. The monitoring of C8 to C7 is disabled and is not enabled even if the short is removed. * If short occurs after power-up, the situation is treated as a zero voltage input for C8 to C7. ALRML goes high when the undervoltage is enabled. Open (or Disconnected) ALRML goes high as it causes an overvoltage to the affected input pair even if the overvoltage is set to the maximum. Short to Pin 10 * If short occurs before power-up, the part works as if C7 does not exist because the internal circuit detects the situation and assumes it is what the application intended to do. The monitoring of C7 to C6 is disabled and is not enabled even if the short is removed. * If short occurs after power-up, the situation is treated as a zero voltage input for C7 to C6. ALRML goes high when the undervoltage is enabled. Open (or Disconnected) ALRML goes high as it causes an overvoltage to the affected input pair even if the overvoltage is set to the maximum. Short to Pin 11 * If short occurs before power-up, the part works as if C6 does not exist because the internal circuit detects the situation and assumes it is what the application intended to do. The monitoring of C6 to C5 is disabled and is not enabled even if the short is removed. * If short occurs after power-up, the situation is treated as a zero voltage input for C6 to C5. ALRML goes high when the undervoltage is enabled. Open (or Disconnected) ALRML goes high as it causes an overvoltage to the affected input pair even if the overvoltage is set to the maximum. Short to Pin 12 * If short occurs before power-up, the part works as if C5 does not exist because the internal circuit detects the situation and assumes it is what the application intended to do. The monitoring of C5 to C4 is disabled and is not enabled even if the short is removed. * If short occurs after power-up, the situation is treated as a zero voltage input for C5 to C4. ALRML goes high when the undervoltage is enabled. Open (or Disconnected) ALRML goes high as it causes an overvoltage to the affected input pair even if the overvoltage is set to the maximum. Short to Pin 13 * If short occurs before power-up, the part works as if C4 does not exist because the internal circuit detects the situation and assumes it is what the application intended to do. The monitoring of C4 to C3 is disabled and is not enabled even if the short is removed. * If short occurs after power-up, the situation is treated as a zero voltage input for C4 to C3. ALRML goes high when the undervoltage is enabled. C8 C7 C6 C5 C4 ______________________________________________________________________________________ 23 MAX11080 Table 4. FEMA Analysis (Note 5) (continued) MAX11080 12-Channel, High-Voltage Battery-Pack Fault Monitor Table 4. FEMA Analysis (Note 5) (continued) PIN NUMBER 13 14 15 16 17 18 19 24 NAME ACTION EFFECT Open (or Disconnected) ALRML goes high as it causes an overvoltage to the affected input pair even if the overvoltage is set to the maximum. Short to Pin 14 * If short occurs before power-up, the part works as if C3 does not exist because the internal circuit detects the situation and assumes it is what the application intended to do. The monitoring of C3 to C2 is disabled and is not enabled even if the short is removed. * If short occurs after power-up, the situation is treated as a zero voltage input for C5 to C4. ALRML goes high when the undervoltage is enabled. Open (or Disconnected) ALRML goes high as it causes an overvoltage to the affected input pair even if the overvoltage is set to the maximum. Short to Pin 15 * If short occurs before power-up, the part works as if C2 does not exist because the internal circuit detects the situation and assumes it is what the application intended to do. The monitoring of C2 to C1 is disabled and is not enabled even if the short is removed. * If short occurs after power-up, the situation is treated as a zero voltage input for C2 to C1. ALRML goes high when the undervoltage is enabled. Open (or Disconnected) ALRML goes high as it causes an overvoltage to the affected input pair even if the overvoltage is set to the maximum. Short to Pin 16 ALRML goes high irrespective of whether undervoltage is enabled/disabled and before and after power-up. Open (or Disconnected) ALRML goes high irrespective of whether undervoltage is enabled/disabled and before and after power-up. Short to Pin 17 * ALRML goes high if pin 17 is pulled high by VAA. The part consumes a large current as VAA is shorted to AGND (connected to C0). * If pin 17 is tied to AGND, there is no effect. Open (or Disconnected) The pin defaults to low due to the internal pulldown (see Note 7). The effect depends on the intended undervoltage setting. Short to Pin 18 * If pin 17 and pin 18 have the same intended value, there is no effect for the short. * If pin 17 and pin 18 have a different setting, the VAA is shorted to AGND. ALRML goes low. Open (or Disconnected) The pin defaults to low due to the internal pulldown (see Note 7). The effect depends on the intended undervoltage setting. Short to Pin 19 * If pin 18 and pin 19 have the same intended value, there is no effect for the short. * If pin 18 and pin 19 have a different setting, the VAA is shorted to AGND. ALRML goes low. Open (or Disconnected) The pin defaults to low due to the internal pulldown (see Note 7). The effect depends on the intended undervoltage setting. Short to Pin 20 * If pin 19 and pin 20 have the same intended value, there is no effect for the short. * If pin 19 and pin 20 have the different setting, the VAA is shorted to. AGND ALRML goes low. C3 C2 C1 C0 UVSEL0 UVSEL1 UVSEL2 ______________________________________________________________________________________ 12-Channel, High-Voltage Battery-Pack Fault Monitor PIN NUMBER 20 21 22 23 NAME Open (or Disconnected) The pin defaults to low due to the internal pulldown (see Note 7). The effect depends on the intended overvoltage setting. Short to Pin 22 * If pin 21 and pin 22 have the same intended value, there is no effect for the short. * If pin 21 and pin 22 have a different setting, the VAA is shorted to AGND. ALRML goes low. Open (or Disconnected) The pin defaults to low due to the internal pulldown (see Note 7). The effect depends on the intended overvoltage setting. Short to Pin 23 * If pin 22 and pin 23 have the same intended value, there is no effect for the short. * If pin 22 and pin 23 have a different setting, the VAA is shorted to AGND. ALRML goes low. Open (or Disconnected) The pin defaults to low due to the internal pulldown (see Note 7). The effect depends on the intended overvoltage setting. Short to Pin 24 * If pin 23 is set high, there is no effect for the short. * If pin 23 is set low, the VAA is shorted to AGND. ALRML goes low. Open (or Disconnected) ALRML goes high. Short to Pin 25 ALRML goes low. Open (or Disconnected) VAA goes to approximately 100mV and ALRML is approximately 0.5V. There is no heartbeat if there is a one before the opening. Short to Pin 26 The device is in shutdown mode. ALRML is low. Open (or Disconnected) The pin is internally pulled down and the device goes to the shutdown mode. ALRML is low. Short to Pin 27 ALRML goes high and stays high even if the short is removed. The internal detect circuit considers this a major failure and the part has to be repowered up to come out of this state. Open (or Disconnected) The signal at the ALRML cannot be seen by the host. Short to Pin 28 ALRML goes high and stays high even if the short is removed. The internal detect circuit considers this a major failure and the part has to be repowered up to come out of this state. Open (or Disconnected) The delay between the fault condition and alarm setting (ALRML goes high) goes to the minimum. This means there is almost no delay. Short to Pin 29 The delay between the fault condition and alarm setting (ALRML goes high) is approximately 4s, which is set by the internal watchdog. OVSEL3 AGND 28 Short to Pin 21 * If pin 20 and pin 21 have the same intended value, there is no effect for the short. * If pin 20 and pin 21 have a different setting, the VAA is shorted to AGND. ALRML goes low. OVSEL2 25 27 The pin defaults to low due to the internal pulldown (see Note 7). The effect depends on the intended overvoltage setting. OVSEL1 VAA SHDN ALRML EFFECT Open (or Disconnected) OVSEL0 24 26 ACTION CD ______________________________________________________________________________________ 25 MAX11080 Table 4. FEMA Analysis (Note 5) (continued) MAX11080 12-Channel, High-Voltage Battery-Pack Fault Monitor Table 4. FEMA Analysis (Note 5) (continued) PIN NUMBER NAME 29 AGND 30 31 AGND EFFECT Open (or Disconnected) No effect. Short to Pin 30 No effect. Open (or Disconnected) No effect. Short to Pin 31 If pin TOPSEL is set high (VAA), it causes the short between VAA and AGND. ALRML is low. There is no effect if TOPSEL is set low. Open (or Disconnected) If the part is the topmost device in the daisy chain, the ALRML is set high as the state of TOPSEL is low (internally pulled down). There are no other effects as the state of the pin stays the same (both low). Short to Pin 32 No effect if TOPSEL is set low. If TOPSEL is set high, it causes the short between VAA and AGND and ALRML is low. TOPSEL 32 AGND 33 N.C. 34 ACTION Open (or Disconnected) No effect. Short to Pin 33 No effect. Open (or Disconnected) No effect. Short to Pin 34 No effect. Open (or Disconnected) ALRMU is internally pulled up to VDDU. There is no effect to the topmost device. Otherwise, the communication of the chain is broken and the alarm signal from the parts close to the topmost device are not passed through. Since ALRML is a reflection of ALRMU, the state of ALRML is high for the noalarm state. Short to Pin 35 No effect for the topmost device. Otherwise, the communication of the chain is broken and the alarm signal from the parts close to the topmost are not passed through. Since ALRML is a reflection of ALRMU, the state of ALRML is low for the no-alarm state. Open (or Disconnected) The ALRML goes high. VDDU floats down approximately 4V. (See Note 8.) Short to Pin 36 The ALRML is high. (See Note 8). Open (or Disconnected) ALRML goes high. HV is approximately 0.4V below DCIN. (See Note 8.) Short to Pin 37 ALRML goes high. VDDU is approximately 0.5V lower than GNDU. (See Note 8.) Open (or Disconnected) ALRML goes high. VDDU and HV collapse. Short to Pin 38 ALRML goes high. VDDU is approximately 0.5V lower than GNDU. (See Note 8.) Open (or Disconnected) ALRML goes high. VDDU and HV collapse. (See Note 8.) ALRMU 35 GNDU 36 VDDU 37 CP- 38 CP+ Note 5: If the cell voltage is within the monitor range, the heartbeat signal on the ALRML resumes once the fault condition is removed. Note 6: The voltage level of high is equal to VAA and low is equal to AGND. Note 7: Even if the pin has internal pulldown, the pulldown is very weak and the pin should be tied to AGND for logic 0 setting. Note 8: VDDU - GNDU = 3.3 - V and HV - DCIN = 3.6V for the typical configuration. When VDDU and HV collapse, VDDU - GNDU 0 - V and HV - DCIN -0.4V. 26 ______________________________________________________________________________________ 12-Channel, High-Voltage Battery-Pack Fault Monitor Package Information For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. TOP VIEW DCIN 1 HV + 38 CP+ 2 37 CP- N.C. 3 36 VDDU C12 4 35 GNDU C11 5 34 ALRMU C10 6 33 N.C. C9 7 32 AGND C8 8 31 TOPSEL C7 9 30 AGND C6 10 29 AGND C5 11 28 CD C4 12 27 ALRML C3 13 26 SHDN C2 14 25 AGND C1 15 24 VAA C0 16 23 OVSEL3 UVSEL0 17 22 OVSEL2 UVSEL1 18 21 OVSEL1 UVSEL2 19 20 OVSEL0 MAX11080 PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 38 TSSOP U38-1 21-0081 TSSOP Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 27 (c) 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc. MAX11080 Pin Configuration