L6377_08 STMICROELECTRONICS | Alldatasheet

Document overview

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Technical content

Datasheet sections

  • 1 Maximum rating
  • 1.1 Absolute maximum ratings
  • 1.2 Thermal data
  • 2 Pin connections
  • 3 Electrical characteristics
  • 4 Input section
  • 5 Over temperature protection (OVT )
  • 6 Under voltage protection (UV)
  • 7 Over current operation
  • 8 Demagnetisation of induct ive loads
  • 9 Package mechanical data
  • 10 Revision history

Features

■ Multipower BCD technology ■ 0.5 A output current ■ 8 to 35 V supply voltage range ■ Externally programmable current limit ■ Non-dissipative over-current protection ■ Thermal shutdown ■ Under voltage lockout with hysteresys ■ Diagnostic output for under voltage, over temperature and over current ■ External asynchronous reset input ■ Presettable delay for overcurrent diagnostic ■ Open ground protection ■ Protection against surge transient (IEC 61000-4-5) ■ Immunity against burst transient (IEC 61000-4-4)

Description

This device is a monolithic intelligent power switch in multipower BCD technology for driving inductive, capacitive or resistive loads. Diagnostic for CPU feedback and extensive use of electrical protections make this device inherently indistructible and suitable for general purpose industrial applications. Table 1. Device summary Figure 1. Block diagram

1 Maximum rating

1.1 Absolute maximum ratings

1.2 Thermal data

Table 2. Absolute maximum ratings Table 3. Thermal data

2 Pin connections

Figure 2. Pin connections (top view) Table 4. Pin description

2 GND Ground pin

5 Rsc Current limiting setting

10 ON DELAY Delay setting for overcurrent diagnostic

11 DIAG Diagnostic open drain output for over temperature, under voltage and

12 IN+ Comparator non inverting input

13 RESET Asynchronous reset input

3 Electrical characteristics

Table 5. Electrical characteristcs

Table 5. Electrical characteristcs (continued)

4 Input section

An Input and Asynchronous RESET, both TTL/CMOS compatible with wide voltage range and high noise immunity (thanks to a built in hysteresis) are available.

5 Over temperature protection (OVT)

An on-chip Over Temperature Protection provides an excellent protection of the device in extreme conditions. Whenever the temperature - measured on a central portion of the chip- exceeds T max =150 °C (typical value) the device is shut off, and the DIAG output goes LOW. Normal operation is resumed as the chip temperature (normally after few seconds) falls below Tmax-Thys = 130 °C (typical value). The hysteresis avoid thats an intermittent behaviour take place.

6 Under voltage protection (UV)

The supply voltage is expected to range from 8 to 35 V. In this range the device operates correctly. Below 8V the overall system has to be considered not reliable. To avoid any misfunctioning the supply voltage is continuously monitored to provide an under voltage protection. As V s falls below Vsth-Vshys (typically 7.5 V, see fig. 4) the output power MOS is switched off and DIAG output goes LOW. Normal operation is resumed as soon as Vs exceeds Vsth. The hysteretic behaviour prevents intermittent operation at low supply voltage.

7 Over current operation

Isc is limited to Isc = 1.1 A (typical value). Figure 5. Short circuit operation waveforms

Over current operation L6377 When also the tOFF interval has expired, the output power MOS is switched ON. Now two conditions may occur

  • the overload is still present. In this case the output power MOS is again driven in linear mode (limiting the output current to Isc) for another tON, starting a new cycle, or
  • the overload condition is removed, and the output power MOS is no longer driven in linear mode. All these occurrences are presented on the DIAG pin (see fig 5). We call this unique feature non dissipative short circuit protection and it ensures a very safe operation even in permanent overload conditions. Note that, of course, choosing the most appropriate value for the t ON interval (i.e. the value of the CDON capacitor) a delay (the tON itself) will prevent that a misleading Short Circuit information is presented on the DIAG output, when driving capacitive loads (that acts like short circuit in the very beginning) or Incandescent Lamp (a cold filament has a very low resistive value). The non dissipative short circuit protection can be disabled (keeping t ON = 0 but with the output current still limited to Isc, and Diagnostic disabled) simply shorting to ground the the ON DELAY pin.

8 Demagnetisation of inductive loads

for demagnetisation versus Vs. Figure 7. External demagnetisation circuit (versus ground) Figure 6. Input comparator hysteresis

Figure 8. External demagnetisation circuit (versus )

9 Package mechanical data

In order to meet environmental requirements, ST offers these devices in ECOPACK® packages. These packages have a lead-free second level interconnect . The category of second level interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an ST trademark. ECOPACK specifications are available at: www.st.com

Figure 9. Package dimensions Table 6. SO-14 mechanical data

Table 7. Document revision history