ATA5278_06 ATMEL [ATMEL Corporation], ATA5278_06 Datasheet
ATA5278_06
Related parts for ATA5278_06
ATA5278_06 Summary of contents
Page 1
Features • SPI for Microcontroller Connection with Mbit/s • Internal Data Buffer for Timing-independent Data Transmission • Programmable Driver Current Regulation • One-chip Antenna Driver Stage for 1A Peak Current • LF Baud Rates Between 1 kbaud ...
Page 2
Figure 1-1. Block Diagram VL1 VL2 VL3 PGND1 PGND2 PGND3 VDS CBOOST DRV1 QSC VSHUNT AGND 2. Pin Configuration Figure 2-1. Pinning QFN28 ATA5278 2 CINT VBATT VDD Boost 5-V converter regulator control ATA5278 HS driver Driver control LS driver ...
Page 3
Table 2-1. Pin Description Pin Symbol Function 1 PGND1 Boost transistor ground 2 PGND2 Boost transistor ground 3 PGND3 Boost transistor ground 4 VDS Driver voltage supply input 5 DRV1 Antenna driver stage output 6 CBOOST External bootstrap capacitor connection ...
Page 4
Functional Description 3.1 General Description The IC contains a half-bridge coil driver stage with a special driver voltage regulator and control logic with diagnosis circuitry controllable by a serial programming interface (SPI). In combination with an LC ...
Page 5
Figure 3-1. The startup time, t cal oscillation build-up times are below 100 µs for ceramic and about 1 ms for crystal resonators. When using an active clock source, the startup time can be neglected. The internal logic debounces the ...
Page 6
In case the microcontroller is not able to communicate properly with the ATA5278 or any other disturbance has occurred, it can trigger a reset (like a power-on-reset, POR) in the chip by pull- ing the NRES pin to ground, which ...
Page 7
The main element of this circuit is the parallel inverting stage which generates the clock signal in conjunction with the external reference device. During power-down mode, these inverters are shut down and the pull-down structure on the OSCI pin is ...
Page 8
SPI The control interface of the ATA5278 consists of an eight-bit synchronous SPI. It has a clock input (S_CLK) which supports frequencies MHz, a chip select line (S_CS) which enables the interface, a serial data input ...
Page 9
Figure 3-7. SPI Timing Diagram t DO,enable S_CS S_CLK X S_DI X S_DO Z t DO,enable S_CS S_CLK X S_DI X S_DO Z 3.7 SPI Commands The microcontroller can access the following functions of the ATA5278 via the SPI: • ...
Page 10
Table 3-1. SPI Commands No. I/O MSB ...
Page 11
Command Description Table 3-1 on page 10 ATA5278. Each command consists of one or more data words which the controller has to trans- fer to the SPI of the ATA5278. An SPI data word is always eight bits in ...
Page 12
The status register of the ATA5278 can be read out with command 9. As soon as the internal diagnosis stage detects a fault stored in the status register until a fault reset command is given or a ...
Page 13
Figure 3-8. The buffer is structured into two parallel blocks with the same storage capacity. The reason for this is that the LF data is handled as logical (e.g., Manchester coded) bits, where each data is encoded by two so-called ...
Page 14
Figure 3-9. LF Data Modulation with ASK Half bit X values Driver control input Driver control signal Resulting antenna signal MODACTIVE pin Start of modulation The LF data stream in get this result, a hex value of 0F6h has to ...
Page 15
The carrier signal is now always on as long as the LF data is in the buffer only at the change of the LF data values that the phase of the antenna current is shifted by 180°. For ...
Page 16
The gate of the external transistor is driven by the QSC pin of the ATA5278. The signal provided here is suited to drive standard MOSFETs (i.e., no logic-level FETs). During power-down mode or a fault shutdown, the external transistor is ...
Page 17
The antenna driver stage and the boost converter are thermally monitored in order to protect them from overheating, and the output pin DRV1 is short-circuit protected by means of current limitation. For further details, please refer to the section The ...
Page 18
Figure 3-14. Integrator Output Current on CINT Pin As can be seen in from the external capacitor depending on the voltage at the VSHUNT pin. Note that the shown values for VSHUNT are only valid if maximum antenna current (i.e., ...
Page 19
Current Adjustment The maximum reachable output current in the antenna circuit can be calculated as follows: I ant,eff Here, V the R DSon calculating the amount of complex Z, that the antenna driver output frequency (i.e ...
Page 20
Fault Diagnosis The IC contains several fault diagnosis systems to protect itself from destruction and to provide diagnosis information fault at the power stages is detected for a certain debounce time, both the switch mode power supply ...
Page 21
Figure 3-15. Fault Shutdown Timing t < t deb,min Internal fault signal Driver output stage Boost converter operation QSC gate signal MODACTIVE pin Note: Internal fault signal rises as soon as a fault (overtemperature, short-circuit or open load) is detected ...
Page 22
MODACTIVE Output Pin The MODACTIVE pin of the ATA5278 can be used to directly control a timer/counter stage of the microcontroller. The signal indicates LF data modulation activity. In conjunction with suited timers and counting stages in the microcontroller, ...
Page 23
The external components used in this schematic are listed in Table 3-5. Element XTAL T1 The following basic hints should be considered when designing an application with the ATA5278. • Principally, the ...
Page 24
The ground pin possible. The same is true for the connection between L1, D2 and VL1..3 and the connection between D2, the positive pin of C4 and the VDS pin. Note that in any case, the ...
Page 25
Figure 3-18. Operation Cycle Duration versus Power Dissipation Note that the upper limit of this diagram (0.6s) is not a design parameter but just for representa- tion reasons. The graphs continue to increase beyond the top line. For this diagram, ...
Page 26
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 ...
Page 27
Electrical Characteristics 6.5V < V < 16.5V 25°C unless otherwise specified. All values refer to GND pins. 6V possible with approximately 30% decrease BATT amb of maximum output power, 28-V operation possible (jump start), but output current ...
Page 28
Electrical Characteristics (Continued) 6.5V < V < 16.5V 25°C unless otherwise specified. All values refer to GND pins. 6V possible with approximately 30% decrease BATT amb of maximum output power, 28-V operation possible (jump start), but output ...
Page 29
Electrical Characteristics (Continued) 6.5V < V < 16.5V 25°C unless otherwise specified. All values refer to GND pins. 6V possible with approximately 30% decrease BATT amb of maximum output power, 28-V operation possible (jump start), but output ...
Page 30
Electrical Characteristics (Continued) 6.5V < V < 16.5V 25°C unless otherwise specified. All values refer to GND pins. 6V possible with approximately 30% decrease BATT amb of maximum output power, 28-V operation possible (jump start), but output ...
Page 31
Electrical Characteristics (Continued) 6.5V < V < 16.5V 25°C unless otherwise specified. All values refer to GND pins. 6V possible with approximately 30% decrease BATT amb of maximum output power, 28-V operation possible (jump start), but output ...
Page 32
Electrical Characteristics (Continued) 6.5V < V < 16.5V 25°C unless otherwise specified. All values refer to GND pins. 6V possible with approximately 30% decrease BATT amb of maximum output power, 28-V operation possible (jump start), but output ...
Page 33
Ordering Information Extended Type Number ATA5278-PKQI 10. Package Information 4832C–RKE–02/06 Package Remarks QFN28 mm, taped and reeled, Pb-free ATA5278 33 ...
Page 34
Atmel Corporation 2325 Orchard Parkway San Jose, CA 95131, USA Tel: 1(408) 441-0311 Fax: 1(408) 487-2600 Regional Headquarters Europe Atmel Sarl Route des Arsenaux 41 Case Postale 80 CH-1705 Fribourg Switzerland Tel: (41) 26-426-5555 Fax: (41) 26-426-5500 Asia Room 1219 ...