 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
908E621 Datasheet(PDF) 39 Page - Freescale Semiconductor, Inc |
|
||||||||||||||||||||||||||||||
908E621 Datasheet(HTML) 39 Page - Freescale Semiconductor, Inc |
|
|
39 / 60 page  Analog Integrated Circuit Device Data Freescale Semiconductor 39 908E621 FUNCTIONAL DEVICE OPERATION OPERATIONAL MODES High Side Over-voltage / Under-voltage Protection The outputs are protected against under /over-voltage conditions. This protection is done by the low and high voltage interrupt circuitry. If an over /under-voltage condition is detected (LVIF / HVIF), and Bit VIS in the High Side Status Register is cleared, the output is disabled. The over /under-voltage status flags are cleared (and the output reenabled), by writing a logic [1] to the LVIF / HVIF flags in the Interrupt Flag Register, or by reset. Clearing this flag has no effect as long as a high or low voltage condition is present. HIGH SIDE OVER-TEMPERATURE PROTECTION The outputs are protected against over-temperature conditions. Each power output comprises two different temperature thresholds. The first threshold is the high temperature interrupt (HTI). If the temperature reach this threshold, the HTI bit in the interrupt flag register is set and an interrupt will be generated, if the HTIE bit in the interrupt mask register is set. In addition, this interrupt can be used to automatically turn off the power stages (all high sides, on Half-bridges just the high side FET’s). This shutdown can be enabled/disabled by the HTIS0 bit. The high temperature interrupts flag (HTIE) is cleared (and the outputs reenabled) by writing a logic [1] to the HTIF flag in the Interrupt Status Register, or by reset. Clearing this flag has no effect as long as a high temperature condition is present. If the HTIS shutdown is disabled, a second threshold (HTR) will be used to turn off all power stages (HB (all Fet’s), HS, HVDD, H0) in order to protect the device. High Side Over-current Protection The HS outputs are protected against over-current. When the over-current limit is reached, the output will be automatically switched off and the over-current flag is set. Due to the high inrush current of bulbs, a special feature was implemented to avoid a over-current shutdown during this inrush current. If a PWM frequency will be supplied to the PWM input during the switch on of a bulb, the inrush current will be limited to the over-current shutdown limit. This means, if the current reaches the over-current shutdown, the high side will be switched off, but each rising edge on the PWM input will enable the driver again. The duty cycle supplied by the MCU has no influence on the switch-on time of the high side driver. In order to distinguish between a shutdown due to an inrush current or a real shutdown, the software checks if the over-current status flag (HSxOCF) in the High Side Status register is set beyond a certain period of time. Table 9. High Side Configuration Bits HSxPWM HSxON Mode 0 0 High side MOSFET off 0 1 High side MOSFET on if over-current, the over-current flag (HSxOCF) is set, and the high side MOSFET is turned off 1 0 In this mode, the PWM duty cycle is either controlled by the PWM input signal, or if the over-current shutdown value is reached by the part itself. Without reaching the over-current shutdown, the high side driver is directly driven from the PWM input signal. If the Input signal is high, the output is on. If low, the output is off (PWM control). If the current reaches the over-current shutdown value, the high side will be automatically turned off. With the next rising edge of the PWM input signal, the output will turn on again (current limitation). The HSxOCF bit will be set. The software has to distinguish between an inrush current and a real short on the output. 1 1 High side MOSFET is switched on and the inrush current limitation is enabled. This means the high side will start automatically with a current limitation around the over-current shutdown threshold. (PWM signal must be applied, see Figure 24) If the high side enters current limitation, the HSxOCF bit is set, but the output is not disabled. The software needs to distinguish between an inrush current and a real short on the output. |
Similar Part No. - 908E621_12 |
|
Similar Description - 908E621_12 |
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.COM |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
