U6813B ATMEL Corporation, U6813B Datasheet
U6813B
Available stocks
Related parts for U6813B
U6813B Summary of contents
Page 1
... The function of microcontrollers in safety-critical applications (e.g., anti-lock systems) needs to be monitored permanently. Usually, this task is accomplished by an indepen- dent watchdog timer. The monolithic IC U6813B, designed in bipolar technology and qualified according to the needs of the automotive industry, includes such a watchdog timer and provides additional features for added value. With the help of integrated driver stages easy to control safety-related functions of a relay and of an N-chan- nel power MOSFET in high-side applications ...
Page 2
... Figure 1-1. Block Diagram 3 3.3-V under- and overvoltage detect 5-V under- and overvoltage detect. RELI 13 19k FETI 12 19k 11 WDI 19k U6813B 2 Bandgap Power-on reference reset 2.44 V Reset Reset debounce delay fosc fosc Internal oscillator fosc RC- oscillator supervisor Watchdog RC oscillator SGND GND WDC ...
Page 3
... Voltage for charge pump Input bootstrap capacitor High voltage for N-channel FET External RC for watchdog timer Watchdog trigger signal Activation of power FET Activation of relay driver 5-V supply Sense ground, reference for V 3.3-V supply U6813B Type Driver on: L Reset: H Reset: L Enable: H Enable: L Pulse sequence FET on: H Driver on: H and 3 ...
Page 4
... A critical status means, for example, if the system is not able to switch off the relay or disable the power MOSFET the system is not able to provide a signal to the microcontroller via ENABLE- and RESET-outputs in the case of a fault condition. The U6813B is designed to han- dle those fault conditions according to Table 3-1 ...
Page 5
... The watchdog’s = 100 f . WDI Figure 4-3, Watchdog State Diagram), 170/ f 250/ f WDC WDC Update rate is Update rate is too slow either too slow or pulse has dropped out U6813B which is fed to the WDI 251/ f WDC Pulse has dropped out 5 ...
Page 6
... WDC WDI WDI pulse width for fault detection after 3 pulses: Upper watchdog window Minimum: 169/ f Maximum: 170/ f Lower watchdog window Minimum: 79/ f Maximum: 80/ f U6813B 6 Watchdog State Diagram good Initial status 1/NF bad bad O/F bad good 1/F good < 200 k due to leakage current and humidity) ...
Page 7
... Ambient temperature range Storage temperature range 6. Thermal Resistance Parameters Junction ambient 4543B–AUTO–10/05 = 50.0 ms WDC = 50.2 ms WDC Symbol tot P tot amb T stg Symbol R thJA U6813B Value Unit –0.2 to +26 250 mW 150 mW 150 –40 to +125 –55 to +155 Value Unit 110 K/W V °C °C °C 7 ...
Page 8
... Input current low Input voltage = 0V 4.5 Input current high Input voltage = 5V *) Type means 100% tested 100% correlation tested Characterized on samples Design parameter Note > the current has to be limited external resistor. S U6813B Hz, bootstrap capacitor C WDI Pin Symbol – ...
Page 9
... SAT6 0.5V I 0.5 LEAK6 R 25 100 INT6 t 120 320 500 DEB6 t 85 DEL6 V 0.5 SAT5 I 0.5 LEAK5 R 12.5 50 INT5 t 120 320 500 DEB5 t 85 DEL5 U6813B Unit Type µA A µ µ µ µ µ ...
Page 10
... Hysteresis 13.4 Reset debounce time 13.5 Reset delay 13.6 Current *) Type means 100% tested 100% correlation tested Characterized on samples Design parameter Note > the current has to be limited external resistor. S U6813B Hz, bootstrap capacitor C WDI Pin Symbol 150 ...
Page 11
... POR 81.9 246 RCerror t 0.16 0.64 D,OUV t 0.187 0.72 R,OUV WDI f 1 6.5 WDC t 364 P,WDI f 32.35 56.25 WDI n 3 lock 3 release 49 51 WDIerror 2 80 170 1 250 251 U6813B Unit Type* kHz kHz D µ cycles A cycles D cycle A cycles A 11 ...
Page 12
... Pulse 5) Pulse Voltage 1 –110V 2 +110V 3a –160V 3b +150V 5 55V Note the case of the relay driver, the coil resistance Timing Diagrams Figure 9-1. U6813B 12 (1) Source Resistance Rise Time 10 100V/s 10 100V/s 50 30V/ns 50 20V/ns 2 10V/ms = 150 has to be added to the source resistance. min ...
Page 13
... RELO Batt FETO P- N- N-RES P-RES 0 V Reset debounce time 1st Reset delay WDI too slow Normal operation Don't care < 120 µs >5 good WDI pulses Don't care 2nd Reset delay U6813B 14196 13 ...
Page 14
... P-RES 0 V Reset debounce time 1st Reset delay From C FET in Relay in Sense ground 47n 3.3V SGND VCC RELI U6813B RELO GND P-RES N-RES <120 µs <4 good WDI pulses 2nd Reset delay Watchdog in 1k 36k 2.7M 12 ...
Page 15
... Package Remarks SO16 Taped and reeled, Pb-free 10.0 9.85 0.4 1.27 8. History Put datasheet in a new template Pb-free logo on page 1 added New heading rows on Table “Absolute Maximum Ratings” on page 7 added Table “Ordering Information” on page 15 changed 5.2 4.8 3.7 1.4 0.2 0.25 3.8 0.10 6.15 5.85 technical drawings according to DIN specifications U6813B 15 ...
Page 16
... Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel’s products are not intended, authorized, or warranted for use as components in applications intended to support or sustain life. © Atmel Corporation 2005. All rights reserved. Atmel marks or trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others. Atmel Operations Memory ...