Dual Triple DMOS Output Driver

Dual Triple DMOS Output Driver with Serial Input Control T6817 1. Introduction The T6817 is a fully-protected universal driver interface designed in 0.8-µm BCDMOS technology. It is used to control up to 6 different loads by a microcontroller in automotive and industrial applications. Each of the 3 high-side and 3 low-side drivers is capable of driving currents up to 600 mA. The drivers are freely configurable and can be controlled separately from a standard serial data interface. Therefore, all kinds of loads such as bulbs, resistors, capacitors, and inductors can be combined. The IC design particularly supports applications of H-bridges to drive DC motors. Protection against short-circuit conditions, overtemperature, under- and overvoltage is implemented. Various diagnostic functions and a very low quiescent current in standby mode enable a wide range of applications. Automotive qualification with respect to conducted interferences, EMC and 2-kV ESD protection gives added value www.DataSheet4U.com and enhanced quality for the demands of highly-sophisticated applications. T6817 Driver ICs Application Note 2. Development Board The development board includes the following components: • • • • T6817 design software Link cable to PC 25-lead 1:1 Application note Datasheet “T6817: Dual Triple DMOS Output Driver with Serial Input Control” 2.1 Description By means of the PC-controlled development board, a user can adapt the loads (see Figure 2-2 on page 3) easily via row connector pins. The design software interface controls the development board. Rev. 4783B–AUTO–11/05 2.2 Features • Row connector pins for external loads switched by low- or high-side drivers • Easy adaptation of loads directly on the T6817 application board • Direct switch of loads to VS or GND • Forward/reverse rotation of DC motors by full-bridge application • Paralleling of outputs for powerful applications • PC adaptation via standard SUB-D connectors (plug 3 or plug 4, see Figure 2-2 on page 3) • PC-controlled functions via software user interface • 5-V power supply on-board, activable by jumper J7, J8 • Signaling output state by LED, activable by J1 to J6 Figure 2-1. Block Diagram HS3 12 HS2 14 HS1 16 Osc Fault Detect Fault Detect Fault Detect VS 6 VS DI 2 S C T O L D H S 3 L S 3 H S 2 L S 2 H S 1 L S 1 S R R VS OV protection VCC CS 3 Input Register Output Register Serial Interface Control Logic VS UV protection 19 VCC 7 CLK 4 S I n. u. n. u. n. u. n. u. n. u. n. u. INH 5 P S F I N H S C D n. u. n. u. n. u. n. u. n. u. n. u. H S 3 L S 3 H S 2 L S 2 H S 1 L S 1 T P P-ON Reset 1 GND DO 18 10 VCC GND GND 11 Fault Detect Fault Detect Fault Detect Thermal protection GND 13 GND 8 LS3 LS2 15 LS1 17 20 2 T6817 4783B–AUTO–11/05 Figure 2-2. J4 J5 J6 1k R4 1k R5 1k Plug 4 D4 D5 HS1 HS3 12 Osc Fault Detect 6 VS 2 OV protrection VS 7 C1 100µ C2 100n R7 DI 10k R8 CLK 10k R9 CS 10k R10 INH 10k R11 DO 1k 18 5 P S F I N H S C D H S 3 L S 3 H S 2 L S 2 H S 1 LT SP 1 n. u. n. u. n. n. u. u. n. n. u. u. HS2 D6 HS2 14 16 HS1 1 25 2 Fault Detect Fault Detect VS VS BYV28 VBATT 13V [6..40V] D10 GND Plug 3 J8 3 Input Register Output Register 24 3 23 4 22 T6817 Development Board Schematic 5 21 6 4 Vs UV protection S I S C T n. u. n. u. n. u. n. u. n. u. n. u. S R R O L D H S 3 L S 3 H S 2 L S 2 H S 1 L S 1 20 7 19 8 18 10 19 J7 R13 200 16 11 15 12 1 P-ON Reset VCC 10 GND GND GND 11 C3 10µ C4 100n D9 14 13 VS GND 13 20 GND Fault Detect Fault Detect Fault Detect 1k 1k R1 R2 1k Thermal protection D1 D2 LS1 LS2 D3 R12 1k LS3 LS2 8 15 LS1 17 INH VBATT VCC J9 GND S1 J1 J2 J3 VS OUT1 OUT2 OUT3 Row Conector 1 VBAT VCC GND Row Conector 2 LS3 Enable R3 LM2936 17 Serial Interface Control Logic VCC U1 9 Vcc VCC HS3 R6 4783B–AUTO–11/05 OUT3H OUT2H OUT1H GND Row Conector 1 T6817 3 Figure 2-3. ATAB6817 Basic Application Board Component Placement; Top Side, Top View Figure 2-4. ATAB6817 Basic Application Board Top Side, Top View 4 T6817 4783B–AUTO–11/05 T6817 Figure 2-5. ATAB6817 Basic Application Board Bottom Side, Top View (as if PCB were transparent) 5 4783B–AUTO–11/05 3. Design Software 3.1 Installation The T6817 development board includes the software T6817. The user can also download the software from the company’s website, www.atmel.com. After the download, the installation process can be launched by starting the downloaded .exe file. The T6817.exe file is transferred to a user-defined directory (for example, D:T6817), and the system files are then transferred to the system directories, finishing the installation. The PC parallel port is connected via the enclosed link cable with the development board. Double-clicking on the T6817 icon (refer to Figure 3-1) starts the software user interface. Figure 3-1. Software Icon 3.2 Description The T6817 development board along with the software user interface shows the principal functions of the T6817 and enables the designer to directly create a design according to current needs. The software user interface includes all parts of the T6817 and provides convenient control of the T6817 via the development board. Pre-adjustment of the required input data is realized by means of the adjust register (representing the microcontroller) on the left side in the software user interface (see Figure 3-2 on page 7). By clicking the Send Data button, the preadjusted data (16 bits) is shifted into the input register of the serial data interface and the output drivers are activated in accordance with the 16-bit operation command. For more detailed information regarding the serial data interface, please refer to the datasheet. The Send Data Loop button causes an uninterrupted data transfer. Thus, each output is directly adjusted by switching the accessory bit. The Reset button resets all bits to the start condition. The software is switched off by clicking on the End button. If available, up to three parallel interface ports (LPT1, LPT2 and LPT3) can be selected to establish the proper connection. By default, 3 input registers are set with the following status: • SI = Software inhibit is set high for normal operation • SCT = Short-circuit and overvoltage time delay is set high for a 100 ms/15 ms delay • OLD = Open-load detection is off when set high 6 T6817 4783B–AUTO–11/05 T6817 Before the first dataword is sent, the IC is in standby (inhibit) mode. As soon as the 1st dataword is sent, the IC reports the previous condition, that is, the INH bit register is set in the output. After the second dataword, the INH bit disappears. 1. Set inhibit switch on 2. Select Send Data Loop 3. Select load to operate 3.3 Ordering Information Please contact your appropriate Atmel Sales Office or Distributor. Figure 3-2. Software User Interface 7 4783B–AUTO–11/05 Table 3-1. Bit 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Functions of the Serial Interface Register Bits Function Status register reset (high = reset, the bits PSF, SCD, and overtemperature shutdown in the output data register are set to low) Controls output LS1 (high = switch output LS1 on) Controls output HS1 (high = switch output HS1 on) See LS1 See HS1 See LS1 See HS1 Not used Not used Not used Not used Not used Not used Open-load detection (low = on) Programmable time delay for short-circuit and overvoltage shutdown (short-circuit shut-down delay high/low = 100 ms/12.5 ms, overvoltage shutdown delay high/low = 15 ms/3.5 ms) Software inhibit; low = standby, high = normal operation (data transfer is not affected by the standby function because the digital part is still powered) Input Register SRR LS1 HS1 LS2 HS2 LS3 HS3 n.u. n.u. n.u. n.u. n.u. n.u. OLD SCT 15 SI 4. Applications 4.1 Demonstration Application A typical demonstration application consists of a dual full bridge arrangement with microcontroller and watchdog to control two DC motors. Such a dual H-bridge arrangement with common mid rail allows for independent control of the motors for both directions of rotation. Enter the appropriate dataword according to Table 4-1 on page 9 to set the desired function. When being operated in a safety-critical environment, the use of a separate watchdog IC (such as U5021M) is recommended. If OLD is activated, the open load detection is active for all output stages that are currently switched off. A pull-up current for each high-side switch and a pull-down current for each lowside switch is turned on (open-load detection current IHS1-3, ILS1-3). If VVS - VHS1-3 or VLS1-3 is lower than the open-load detection threshold, an open-load is detected: the corresponding bit of the output in the output register is set to high. Please note that for the proposed demonstration application all low-side drivers of H-bridges are detected as open loads. This behavior is caused by the low-side open-load detection current being larger than its high-side counterpart. This configuration also ensures that with half- or H-bridge applications the open-load detection works in a well-defined way. If, for example, an open load at motor M1 should be detected, HS1 or HS2 has to be switched on, while the diametrical low-side output register LS2 and LS1, respectively, has to be evaluated. 8 T6817 4783B–AUTO–11/05 T6817 If INH is activated (by software inhibit bit SI or hardware inhibit), all activated loads are switched off, but the input and output registers remain set. Short-circuit detection can easily be demonstrated by intentionally false activation of the Hbridge components, for example, HS1 and LS1. The SCD bit in the output register will be set and can be reset by activating the SRR bit. Please note that such activation of SRR just initiates a reset pulse, not a permanent reset state. If any high-side driver is connected to a low-side one to form a half-bridge, switching from HS active to LS active or vice versa with