ATA6824-DK

ATA6824C High Temperature H-bridge Motor Driver DATASHEET Features ● PWM and direction-controlled driving of four externally-powered NMOS transistors ● High temperature capability up to 200°C junction ● A programmable dead time is included to avoid peak currents within the H-bridge ● Integrated charge pump to provide gate voltages for high-side drivers and to supply the gate of the external battery reverse protection NMOS ● 5V/3.3V regulator and current limitation function ● Reset derived from 5V/3.3V regulator output voltage ● A programmable window watchdog ● Battery overvoltage protection and battery undervoltage management ● Overtemperature warning and protection (Shutdown) ● High voltage serial interface for communication ● TPQFP package Description The Atmel® ATA6824C is designed for DC motor control application in automotive high temperature environment like in mechatronic assemblies in the vicinity of the hot engine, e.g. turbo charger. With a maximum junction temperature of 200°C, Atmel ATA6824C is suitable for applications with an ambient temperature up to 150°C. The IC includes 4 driver stages to control 4 external power MOSFETs. An external microcontroller provides the direction signal and the PWM frequency. In PWM operation, the high-side switches are permanently on while the low-side switches are activated by the PWM frequency. Atmel ATA6824C contains a voltage regulator to supply the microcontroller; via the input pin VMODE the output voltage can be set to 5V or 3.3V respectively. The on-chip window watchdog timer provides a pin-programmable time window. The watchdog is internally trimmed to an accuracy of 10%. For communication a high voltage serial interface with a maximum data range of 20kBaud is integrated. 9212G-AUTO-09/13 Figure 1. Block Diagram M CVRES CP VRES RGATE RGATE H2 H1 S1 S2 RGATE RGATE L1 L2 PGND CPLO GND Charge Pump CCP HS Driver 2 HS Driver 1 LS Driver 1 LS Driver 2 VBAT CPIH DG3 OT UV 12V Regulator VG CVG VBAT PBAT OTP 12 bit VINT DG2 DG1 CC Logic Control Vint 5V Regulator CVINT Supervisor OV CCC CC timer RCC Oscillator WD timer RRWD VBAT CP TP1 VBG VBATSW VCC 5V Regulator Serial Interface Bandgap CSIO WD VCC VMODE /RESET TP2 DIR PWM Battery CVCC 2 ATA6824C [DATASHEET] 9212G–AUTO–09/13 SIO Microcontroller RX TX Pin Configuration TP2 VBATSW VBAT VCC PGND L1 L2 PBAT Figure 1-1. Pinning TPQFP32 VMODE VINT RWD CC /RESET WD GND SIO 1 2 3 4 5 6 7 8 32 31 30 29 28 27 26 25 24 23 Atmel YWW 22 21 ATA6824 20 ZZZZZ-AL 19 18 17 9 10 11 12 13 14 15 16 VG CPLO CPHI VRES H2 S2 H1 S1 TX DIR PWM TP1 RX DG3 DG2 DG1 1. Note: YWW ATA6824C ZZZZZ AL Date code (Y = Year - above 2000, WW = week number) Product name Wafer lot number Assembly sub-lot number Table 1-1. Pin Description Pin Symbol I/O 1 VMODE I 2 VINT I/O 3 RWD I 4 CC I/O RC combination to adjust cross conduction time 5 /RESET O Reset signal for microcontroller 6 WD I Watchdog trigger signal 7 GND I Ground for chip core 8 SIO I/O 9 TX I Transmit signal to serial interface from microcontroller 10 DIR I Defines the rotation direction for the motor 11 PWM I PWM input controls motor speed 12 TP1 – Test pin to be connected to GND 13 RX O Receive signal from serial interface for microcontroller 14 DG3 O Diagnostic output 3 15 DG2 O Diagnostic output 2 16 DG1 O Diagnostic output 1 17 S1 I/O Source voltage H-bridge, high-side 1 18 H1 O Gate voltage H-bridge, high-side 1 19 S2 I/O Source voltage H-bridge, high-side 2 20 H2 O Gate voltage H-bridge, high-side 2 21 VRES I/O Gate voltage for reverse protection NMOS, blocking capacitor 470nF/25V/X7R 22 CPHI I 23 CPLO O Function Selector for VCC and interface logic voltage level Blocking capacitor 220nF/10V/X7R Resistor defining the watchdog interval High Voltage (HV) serial interface Charge pump capacitor 220nF/25V/X7R ATA6824C [DATASHEET] 9212G–AUTO–09/13 3 Table 1-1. Pin Description (Continued) Pin 2. ● ● ● ● Function 24 VG I/O Blocking capacitor 470nF/25V/X7R 25 PBAT I Power supply (after reverse protection) for charge pump and H-bridge 26 L2 O Gate voltage H-bridge, low-side 2 27 L1 O Gate voltage H-bridge, low-side 1 28 PGND I Power ground for H-bridge and charge pump 29 VCC O 5V/100 mA supply for microcontroller, blocking capacitor 2.2µF/10V/X7R 30 VBAT I Supply voltage for IC core (after reverse protection) 31 VBATSW O 100 PMOS switch from VVBAT 32 TP2 – Test pin to be connected to GND Parameter values given without tolerances are indicative only and not to be tested in production Parameters given with tolerances but without a parameter number in the first column of parameter table are “guaranteed by design” (mainly covered by measurement of other specified parameters). These parameters are not to be tested in production. The tolerances are given if the knowledge of the parameter tolerances is important for the application The lowest power supply voltage is named GND All voltage specifications are referred to GND if not otherwise stated Sinking current means that the current is flowing into the pin (value is positive) Sourcing current means that the current is flowing out of the pin (value is negative) Related Documents ● ● ● ● 4 I/O General Statement and Conventions ● ● 2.1 Symbol Qualification of integrated circuits according to Atmel® HNO procedure based on AEC-Q100 AEC-Q100-004 and JESD78 (Latch-up) ESD STM 5.1-1998 CEI 801-2 (only for information regarding ESD requirements of the PCB) ATA6824C [DATASHEET] 9212G–AUTO–09/13 3. Application 3.1 General Remark This chapter describes the principal application for which the Atmel® ATA6824C was designed. Because Atmel cannot be considered to understand fully all aspects of the system, application and environment, no warranties of fitness for a particular purpose are given. Table 3-1. Typical External Components (See also Figure 1 on page 2) Component Function Value Tolerance CVINT Blocking capacitor at VINT 220nF, 10V, X7R 50% CVCC Blocking capacitor at VCC 2.2µF, 10V, X7R 50% CCC Cross conduction time definition capacitor Typical 680pF, 100V, COG RCC Cross conduction time definition resistor Typical 10k CVG Blocking capacitor at VG Typical 470nF, 25V, X7R CCP Charge pump capacitor Typical 220nF, 25V, X7R CVRES Reservoir capacitor Typical 470nF, 25V, X7R RRWD Watchdog time definition resistor Typical 51k CSIO Filter capacitor for SIO Typical 220pF, 100V 4. Functional Description 4.1 Power Supply Unit with Supervisor Functions 4.1.1 Power Supply 50% The IC is supplied by a reverse-protected battery voltage. To prevent it from destruction, proper external protection circuitry has to be added. It is recommended to use at least a capacitor combination of storage and HF caps behind the reverse protection circuitry and closed to the VBAT pin of the IC (see Figure 1 on page 2). An internal low-power and low drop regulator (VINT), stabilized by an external blocking capacitor, provides the necessary lowvoltage supply for all internal blocks except the digital IO pins. This voltage is also needed in the wake-up process. The lowpower band gap reference is trimmed and is used for the bigger VCC regulator, too. All internal blocks are supplied by the internal regulator. The internal supply voltage VINT must not be used for any other supply purpose! Nothing inside the IC except the logic interface to the microcontroller is supplied by the 5V/3.3V VCC regulator. A power-good comparator checks the output voltage of the VINT regulator and keeps the whole chip in reset as long as the voltage is too low. There is a high-voltage switch which brings out the battery voltage to the pin VBATSW for measurement purposes. This switch is switched ON for VCC = HIGH and stays ON in case of a watchdog reset. The signal can be used to switch on external voltage regulators, etc. ATA6824C [DATASHEET] 9212G–AUTO–09/13 5 4.1.2 Voltage Supervisor This block is intended to protect the IC and the external power MOS transistors against overvoltage on battery level and to manage undervoltage on it. Function: in case of both overvoltage alarm (VTHOV) and of undervoltage alarm (VTHUV) the external NMOS motor bridge transistors will be switched off. The failure state will be flagged via DG2. No other actions will be carried out. The undervoltage comparator is connected to the pin VBAT while the overvoltage comparator is connected to pin PBAT. Both are filtered by a first-order low pass with a corner frequency of typical 15kHz. 4.1.3 Temperature Supervisor There is a temperature sensor integrated on-chip to prevent the IC from overheating due to a failure in the external circuitry and to protect the external NMOSFET transistors. In case of detected overtemperature (180°C), the diagnostic pin DG3 will be switched to “H” to signalize overtemperature warning to the microcontroller. It should undertake actions to reduce the power dissipation in the IC. In case of detected overtemperature (200°C), the VCC regulator and all drivers including the serial interface will be switched OFF immediately and /RESET will go LOW. Both temperature thresholds are correlated. The absolute tolerance is ±15K and there is a built-in hysteresis of about 10K to avoid fast oscillations. After cooling down below the 170°C threshold; the IC will go into Active mode. The occurrence of overtemperature shutdown is latched in DG3. DG3 stays on high until first WD trigger. 4.2 5V/3.3V VCC Regulator The 5V/3.3V regulator is fully integrated on-chip. It requires only a 2.2µF ceramic capacitor for stability and has 100 mA current capability. Using the VMODE pin, the output voltage can be selected to either 5V or 3.3V. Switching of the output voltage during operation is not intended to be supported. The VMODE pin must be hard-wired to either VINT for 5V or to GND for 3.3V. The logic HIGH level of the microcontroller interface will be adapted to the VCC regulator voltage. The output voltage accuracy is in general < ±3%; in the 5V mode with VVBAT < 9V it is limited to < 5%. To prevent destruction of the IC, the current delivered by the regulator is limited to maximum 100mA to 350mA. The delivered voltage will break down and a reset may occur. Please note that this regulator is the main heat source on the chip. The maximum output current at maximum battery voltage and high ambient temperature can only guaranteed if the IC is mounted on an efficient heat sink. A power-good comparator checks the output voltage of the VCC regulator and keeps the external microcontroller in reset as long as the voltage is too low. Figure 4-1. Voltage Dependence and Timing of VCC Controlled RESET Tres VCC 5V VtHRES /RESET 6 ATA6824C [DATASHEET] 9212G–AUTO–09/13 TdelayRESL Figure 4-2. Correlation between VCC Output Voltage and Reset Threshold VCC 5.15V VCC1 4.9V 4.85V Tracking voltage VCC1-tHRESH VtHRESH 4.1V VCC1-VtHRESH = VCC1 - VtHRESH The voltage difference between the regulator output voltage and the upper reset threshold voltage is bigger than 75mV (VMODE = HIGH) and bigger than 50mV (VMODE = LOW). 4.3 Reset and Watchdog Management The timing basis of the watchdog is provided by the trimmed internal oscillator. Its period TOSC is adjustable via the external resistor RWD. The watchdog expects a triggering signal (a rising edge) from the microcontroller at the WD input within a period time window of TWD. Figure 4-3. Timing Diagram of the Watchdog Function tres tresshort /RESET td td t1 t2 t1 t2 WD ATA6824C [DATASHEET] 9212G–AUTO–09/13 7 4.3.1 Timing Sequence For example, with an external resistor RWD = 33 k ±1% we get the following typical parameters of the watchdog. TOSC = 12.32µs, t1 = 12.1ms, t2 = 9.61ms, TWD = 16.88ms ±10% The times tres = 70ms and td = 70ms are fixed values with a tolerance of 10%. After ramp-up of the battery voltage (power-on reset), the VCC regulator is switched on. The reset output, /RESET, stays low for the time tres, then switches to high. For an initial lead time td (for setups in the controller) the watchdog waits for a rising edge on WD to start its normal window watchdog sequence. If no rising edge is detected, the watchdog will reset the microcontroller for tres and wait td for the rising edge on WD. Times t1 (close window) and t2 (open window) form the window watchdog sequence. To avoid receiving a reset from the watchdog, the triggering signal from the microcontroller must hit the timeframe of t2 = 9.61ms. The trigger event will restart the watchdog sequence. Figure 4-4. TWD versus RWD 60 TWD (ms) 50 typ max 40 30 min 20 10 0 0 20 30 40 50 60 70 80 90 100 RWD (kΩ) If triggering fails, /RESET will be pulled to ground for a shortened reset time of typically 2ms. The watchdog start sequence is similar to the power-on reset. The internal oscillator is trimmed to a tolerance of < ±10%. This means that t1 and t2 can also vary by ±10%. The following calculation shows the worst case calculation of the watchdog period Twd which the microcontroller has to provide. t1min = 0.90  t1 = 10.87ms, t1max = 1.10  t1 = 13.28ms t2min = 0.90  t2 = 8.65ms, t2max = 1.10  t2 = 10.57ms Twdmax = t1min + t2min = 10.87ms + 8.65ms = 19.52ms Twdmin = t1max = 13.28ms Twd = 16.42ms ±3.15ms (±19.1%) Figure 4-4 on page 8 shows the typical watchdog period TWD depending on the value of the external resistor ROSC. A reset will be active for VCC < VtHRESx; the level VtHRESx is realized with a hysteresis (HYSRESth). 8 ATA6824C [DATASHEET] 9212G–AUTO–09/13 4.4 High Voltage Serial Interface A bi-directional bus interface is implemented for data transfer between hostcontroller and the local microcontroller (SIO). The transceiver consists of a low side driver (1.2V at 40mA) with slew rate control, wave shaping, current limitation, and a high-voltage comparator followed by a debouncing unit in the receiver. 4.4.1 Transmit Mode During transmission, the data at the pin TX will be transferred to the bus driver to generate a bus signal on pin SIO. The pin TX has a pull-down resistor included. To minimize the electromagnetic emission of the bus line, the bus driver has an integrated slew rate control and waveshaping unit. In transmit mode, transmission will be interrupted in case of overheating at the SIO driver. 4.4.2 Reset Mode In case of an active reset shown at pin /RESET the pin SIO is switched to low, independent of the temperature. The maximum current is limited to ISIO_LIM_RESET. Figure 4-5. Definition of Bus Timing Parameters tBit tBit tBit TX (input to transmitting Node) tSIO_dom(max) tSIO_rec(min) Thresholds of receiving node 1 THRec(max) VVBAT (Transceiver supply of transmitting node) THDom(max) SIO Signal Thresholds of receiving node 2 THRec(min) THDom(min) tSIO_dom(min) tSIO_rec(max) RX (output of receiving Node 1) trx_pdf(1) trx_pdr(1) RX (output of receiving Node 2) trx_pdr(2) trx_pdf(2) The recessive BUS level is generated from the integrated 30 k pull-up resistor in series with an active diode. This diode prevents the reverse current of VBUS during differential voltage between VSUP and BUS (VBUS > VSUP). ATA6824C [DATASHEET] 9212G–AUTO–09/13 9 4.5 Control Inputs DIR and PWM 4.5.1 Pin DIR Logical input to control the direction of the external motor to be controlled by the IC. An internal pull-down resistor is included. 4.5.2 Pin PWM Logical input for PWM information delivered by external microcontroller. Duty cycle and frequency at this pin are passed through to the H-bridge. An internal pull-down resistor is included. Table 4-1. Status of the IC Depending on Control Inputs and Detected Failures Control Inputs Driver Stage for External Power MOS Comments ON DIR PWM H1 L1 H2 L2 0 X X OFF OFF OFF OFF DG1, DG2 fault or RESET 1 0 PWM ON OFF /PWM PWM Motor PWM forward 1 1 PWM /PWM PWM ON OFF Motor PWM reverse The internal signal ON is high when ● At least one valid WD trigger has been accepted ● ● ● ● No short circuit detected VPBAT is inside the specified range (VPBAT_OV ≤ VPBAT ≤ VTHOV) VVBAT is higher than VTHUV The device temperature is not above shutdown threshold In case of a short circuit, the appropriate transistor is switched off after a blanking time of tSC . In order to avoid cross current through the bridge, a cross conduction timer is implemented. Its time constant is programmable by means of an RC combination. Table 4-2. Status of the Diagnostic Outputs Device Status PBAT_UV SC X X X X X X X X X X X 1 1 Note: 10 VBAT_UV PBAT_OV Diagnostic Outputs OT DG1 DG2 DG3 X X 1 – – 1 Overtemperature warning X 0 X 0 1 – Charge pump failure X 1 X X 0 1 – Overvoltage PBAT 1 X X X 0 1 – Undervoltage VBAT 0 0 1 X 1 0 – Short circuit X 1 1 – Undervoltage PBAT 0 0 0 1 X represents: don’t care – no effect) PBAT_UV: Undervoltage PBAT pin SC: Short circuit drain source monitoring VBAT_UV: Undervoltage of VBAT pin PBAT_OV: Overvoltage of PBAT pin CPOK: Charge pump OK OT: Overtemperature warning ATA6824C [DATASHEET] 9212G–AUTO–09/13 Comments CPOK – Status of the diagnostic outputs depends on device status 4.6 VG Regulator The VG regulator is used to generate the gate voltage for the low-side driver. Its output voltage will be used as one input for the charge pump, which generates the gate voltage for the high-side driver. The purpose of the regulator is to limit the gate voltage for the external power MOS transistors to 12V. It needs a ceramic capacitor of 470nF for stability. The output voltage is reduced if the supply voltage at VBAT falls below 12V. 4.7 Charge Pump The integrated charge pump is needed to supply the gates of the external power MOS transistors. It needs a shuffle capacitor of 220nF and a reservoir capacitor of 470nF. Without load, the output voltage on the reservoir capacitor is VVBAT plus VG. The charge pump is clocked with a dedicated internal oscillator of 100KHz. The charge pump is designed to reach a good EMC level. The charge pump will be switched off for VVBAT > VTHOV. 4.8 Thermal Shutdown There is a thermal shutdown block implemented. With rising junction temperature, a first warning level will be reached at 180°C. At this point the IC stays fully functional and a warning will be sent to the microcontroller. At junction temperature 200°C the drivers for H1, H2, L1, L2, SIO and the VCC regulator will be switched off and a reset occurs. 4.9 H-bridge Driver The IC includes two push-pull drivers for control of two external power NMOS used as high-side drivers and two push-pull drivers for control of two external power NMOS used as low-side drivers. The drivers are able to be used with standard and logic-level power NMOS. The drivers for the high-side control use the charge pump voltage to supply the gates with a voltage of VG above the battery voltage level. The low-side drivers are supplied by VG directly. It is possible to control the external load (motor) in the forward and reverse direction (see Table 4-1 on page 10). The duty cycle of the PMW controls the speed. A duty cycle of 100% is possible in both directions. 4.9.1 Cross Conduction Time To prevent high peak currents in the H-bridge, a non-overlapping phase for switching the external power NMOS is realized. An external RC combination defines the cross conduction time in the following way: tCC (µs) = 0.41  RCC (k)  CCC (nF) (tolerance: ±5% ±0.15µs) The RC combination is charged to 5V and the switching level of the internal comparator is 67% of the start level. The resistor RCC must be greater than 5k and should be as close as possible to 10k, the CCC value has to be ≤ 5nF. Use of COG capacitor material is recommended. The time measurement is triggered by the PWM or DIR signal crossing the 50% level. ATA6824C [DATASHEET] 9212G–AUTO–09/13 11 Figure 4-6. Timing of the Drivers PWM or DIR 50% t tLxHL tLxf tLxLH tLxr 80% tCC Lx 20% t tHxLH tCC tHxr tHxHL tHxf 80% Hx 20% t The delays tHxLH and tLxLH include the cross conduction time tCC. 4.10 Short Circuit Detection To detect a short in H-bridge circuitry, internal comparators detect the voltage difference between source and drain of the external power NMOS. If the transistors are switched ON and the source-drain voltage difference is higher than the value VSC (4V with tolerances) the diagnosis pin DG1 will be set to ‘H’ and the drivers will be switched off. All gate driver outputs (Hx and Lx) will be set to ‘L’. Releasing the gate driver outputs will set DG1 back to ‘L’. With the next transition on the pin PWM, the corresponding drivers, depending on the DIR pin, will be switched on again. There is a PBAT supervision block implemented to detect the possible voltage drop on PBAT during a short circuit. If the voltage at PBAT falls under VPBAT_OK the drivers will be switched off and DG1 will be set to “H”. It will be cleared as soon as the PBAT undervoltage condition disappears. The detection of drain source voltage exceedances is activated after the short circuit blanking time tSC, the short circuit detection of PBAT failures operates immediately. 12 ATA6824C [DATASHEET] 9212G–AUTO–09/13 5. Absolute Maximum Ratings Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Pin Description Pin Name Min Max Unit GND 0 0 V Power ground PGND –0.3 +0.3 V Reverse protected battery voltage VBAT +40 V Reverse current out of pin VBAT Reverse protected battery voltage PBAT Ground Reverse current out of pin –1 mA +40 V PBAT –20 Digital output /RESET –0.3 VVCC + 0.3 V Digital output DG1, DG2, DG3 –0.3 VVCC + 0.3 V 4.9V output, external blocking capacitor VINT –0.3 +5.5 V Cross conduction time capacitor/resistor combination CC –0.3 VVCC + 0.3 V Digital input coming from microcontroller WD –0.3 VVCC + 0.3 V RWD –0.3 VVCC + 0.3 V Watchdog timing resistor Digital input direction control mA DIR –0.3 VVCC + 0.3 V Digital input PWM control + Test mode PWM –0.3 VVCC + 0.3 V 5V regulator output VCC –0.3 +5.5 V VMODE –0.3 VVINT + 0.3 V Digital input 12V output, external blocking capacitor VG +16 V Digital output RX –0.3 VVCC + 0.3 V Digital input TX –0.3 VVCC + 0.3 V Serial interface data pin SIO –27 VVBAT + 2 V Source external high-side NMOS S1, S2 (–2) +30 +40(3) V Gates external low-side NMOS L1, L2 VPGND – 0.3 (2) V (2) V Gates of external high-side NMOS H1, H2 Charge pump CPLO VPBAT + 0.3 V Charge pump CPHI VVRES + 0.3 V Charge pump output Switched VBAT Power dissipation Storage temperature Reverse current Notes: VSx – 1 VVG + 0.3 (4) VRES VBATSW VSx + 16 +40 –0.3 Ptot V VVBAT + 0.3 V (1) 1.4 W +150 °C STORE –55 CPLO, CPHI, VG, VRES, Sx –2 mA –1 mA 1. Lx, Hx May be additionally limited by external thermal resistance 2. x = 1.2 3. t < 0.5s 4. Load dump of t < 0.5s tolerated ATA6824C [DATASHEET] 9212G–AUTO–09/13 13 6. Thermal Resistance Parameters Symbol Value Unit Thermal resistance junction to heat slug Rthjc 125°C 29 VCC2 4.75 (3.2) 5.25 (3.4) V A 2.3 Iload = 0mA to 100mA 29 DC line regulation 50 mV A Line regulation 6V 29 IOS1 2.6 Serial inductance to CVCC including PCB 29 2.7 Serial resistance to CVCC including PCB 2.8 Blocking cap at VCC Typ Max Unit Type*