RT9718BGQW(Z00)

RT9718 Over Voltage Protection IC General Description Features The RT9718 is an integrated circuit optimized to protect low voltage system from abnormal high input voltage (up to 28V). The IC monitors the input voltage, battery voltage and the charging current to make sure all three parameters are operated in normal range. When the input voltage exceeds a certain OVP threshold voltage level, the IC will turn off the power MOSFET within 1μs to remove the power before any damage occurs. The RT9718 also can provide a voltage output without the existence of battery. z The IC also monitors the battery voltage, Once the battery voltage exceeds 4.35V and last for more then 180us blinking time, the RT9718 will turn off the MOSFET. The internal logic control will turn off the power MOSFET permanently when the battery over-voltage event occurs for consecutive 16 times. Ordering Information RT9718 Note : Programmable OCP ` Input OVP ` Battery OVP Withstand High Input Voltage Up to 28V Over Voltage Turn Off Time Less Than 1us High Accuracy Protection Thresholds Over Temperature Protection High Immunity of False Triggering Under Transients Warning Indication Output Enable Input Thermal Enhanced WDFN Package RoHS Compliant and Halogen Free ` z z z z z z z z z Applications z z z z Cellular Phones Digital Cameras PDAs and Smart Phones Portable Instruments Pin Configurations (TOP VIEW) VIN GND NC WRN 1 2 3 4 GND The current in the power MOSFET is also limited to prevent charging the battery with an excessive current. The current limit can be programmed by an external resistor between ILIM and GND. The OCP function also has a 4-bit binary counter that accumulates during an OCP event. When the total count reaches consecutive 16 times, the power MOSFET is turned off permanently unless the input power is recycled. Fully Integrated Protection Function 9 8 7 6 5 VOUT ILIM VB EN WDFN-8L 2x2 Package Type QW : WDFN-8L 2x2 (W-Type) Lead Plating System G : Green (Halogen Free and Pb Free) Z : ECO (Ecological Element with Halogen Free and Pb free) OVP A : 6.80V B : 5.85V C : 6.25V D : 7.20V Marking Information For marking information, contact our sales representative directly or through a Richtek distributor located in your area. Richtek products are : ` RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. ` Suitable for use in SnPb or Pb-free soldering processes. DS9718-02 May 2011 www.richtek.com 1 RT9718 Typical Application Circuit RT9718 1 VIN VIN VOUT 8 CIN 1µF 5 Chip Enable VB 6 7 ILIM 4 WRN EN 2 GND Charger IC (RT9502) COUT 1µF To System RVB 200k + RILIM 25k Battery Functional Pin Description Pin No. Pin Name Pin Function 1 VIN The input power source. The VIN can withstand up to 28V input. 2 GND Analog Ground. 3 NC No Internal Connection. 4 WRN This is an open-drain logic output that turns LOW when any protection event occurs. 5 EN 6 VB Battery voltage monitoring input. This pin is connected to the battery pack positive terminal via an isolation resistor. 7 ILIM Over current protection threshold setting pin. Connect a resistor between this pin and GND to set the OCP threshold. 8 VOUT Output through the power MOSFET. Chip Enable (Active Low). Pull this pin to low or leave it floating to enable the IC and force it to high to disable the IC. The exposed pad must be soldered to a large PCB and connected to GND for maximum thermal dissipation. 9 (Expose Pad) GND Function Block Diagram VIN VOUT VREF Ibias BASE Driver OCP VDD INOVP UVLO EN Control Logic ILIM Buffer BATOVP VB WRN EN Logic OTP www.richtek.com 2 OCP Seting GND DS9718-02 May 2011 RT9718 Absolute Maximum Ratings z z z z z z z z z (Note 1) Supply Input Voltage, VIN -------------------------------------------------------------------------------------------- −0.3V to 28V VOUT, VB --------------------------------------------------------------------------------------------------------------- −0.3V to 7V Other Pins --------------------------------------------------------------------------------------------------------------- −0.3V to 6V Power Dissipation, PD @ TA = 25°C WDFN-8L 2x2 ---------------------------------------------------------------------------------------------------------- 0.606W Package Thermal Resistance (Note 2) WDFN-8L 2x2, θJA ----------------------------------------------------------------------------------------------------- 165°C/W WDFN-8L 2x2, θJC ---------------------------------------------------------------------------------------------------- 20°C/W Junction Temperature ------------------------------------------------------------------------------------------------- 150°C Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260°C Storage Temperature Range ---------------------------------------------------------------------------------------- −65°C to 150°C ESD Susceptibility (Note 3) HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 2kV MM (Machine Mode) -------------------------------------------------------------------------------------------------- 200V Recommended Operating Conditions z z (Note 4) Junction Temperature Range ---------------------------------------------------------------------------------------- −40°C to 125°C Ambient Temperature Range ---------------------------------------------------------------------------------------- −40°C to 85°C Electrical Characteristics (VIN = 5V, TA = 25°C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max 4 -- 6.5 Unit Power On Reset RT9718A Operation Voltage RT9718B RT9718C VIN RT9718D Supply Voltage POR Threshold VPOR VPOR Rising Deglitch Time of POR 4 -- 5.5 4 -- 5.9 4 -- 6.9 2.5 2.7 2.9 V -- 8 -- ms 2.45 -- 2.75 V Under Voltage Lockout Threshold VUVLO VUVLO Falling Input Quiescent Current IQ EN = 0V -- 500 600 Input Shutdown Current ISHDN EN = 5V -- 65 95 V μA Protections RT9718A 6.6 6.8 7 Input OVP RT9718B 5.6 5.85 6 Threshold Voltage RT9718C 6.05 6.25 6.45 7 7.2 7.4 -- 60 100 mV -- -- 1 μs -- 8 -- ms VIN_OVP RT9718D Input OVP Hysteresis Input OVP Propagation Delay Input OVP Recovery Delay VOUT = VIN x 80% V To be continued DS9718-02 May 2011 www.richtek.com 3 RT9718 Parameter Symbol Over Current Protection IOCP Over Current Protection Blanking Time Over Current Recover Delay Battery Over Voltage Protection Test Conditions Min Typ Max Unit 0.93 1 1.07 A -- 180 -- μs -- 64 -- ms 4.3 4.35 4.4 V -4.225 30 -- --- mV V --- 180 8 --- μs ms VVB = 4.4V -- -- 20 nA Rising -- 140 -- °C Hysteresis -- 20 -- °C --- 8 8 --- ms ms 1.5 -- --- -0.4 V V 100 200 400 kΩ -- 0.35 0.8 V -- -- 1 μA -- 200 300 mΩ As RILIM = 25k TOC Threshold Rising VBOVP Hysteresis Battery OVP Falling Threshold Battery OVP Blanking Time Battery OVP Recover Delay TVBOV VB Pin Leakage Current OTP Threshold TSD OTP Recover Delay Soft-Start Time Logic EN Threshold Voltage Logic-High VIH Logic-Low VIL EN Internal Pull Down Resistor WRN Output Logic Low Sink 5mA WRN Output Logic High Leakage Current Power MOSFET On Resistance RON I OUT = 500mA, 4.3V < VIN < 6.5V Note 1. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Note 2. θJA is measured in the natural convection at TA = 25°C on a low effective single layer thermal conductivity test board of JEDEC 51-3 thermal measurement standard. The case position of θJC is on the exposed pad of the packages. Note 3. Devices are ESD sensitive. Handling precaution is recommended. Note 4. The device is not guaranteed to function outside its operating conditions. www.richtek.com 4 DS9718-02 May 2011 RT9718 Typical Operating Characteristics OCP Threshold vs. Input Voltage Input OVP vs. Temperature 1.10 6.80 OCP Threshold (A) Input OVP (V) 6.78 6.76 6.74 6.72 6.70 1.07 1.04 1.01 0.98 6.68 CIN = COUT = 1μF, RILIM = 25kΩ CIN = COUT = 1μF 0.95 6.66 -50 -25 0 25 50 75 100 4.4 125 4.7 5 5.3 Temperature (°C) Battery OVP vs. Input Voltage 6.2 6.5 6.8 Battery OVP vs. Temperature 4.370 4.365 4.365 4.360 4.360 Battery OVP (V) Battery OVP (V) 5.9 Input Voltage (V) 4.370 4.355 4.350 4.345 4.355 4.350 4.345 4.340 4.340 4.335 4.335 CIN = COUT = 1μF CIN = COUT = 1μF, VIN = 5.5V 4.330 4.330 4.5 4.8 5.1 5.4 5.7 6 6.3 -50 6.6 -25 0 Input Voltage (V) 25 50 75 100 125 Temperature (°C) Quiescent Current vs. Input Voltage Quiescent Current vs. Temperature 600 600 500 500 Quiescent Current (µA) Quiescent Current (µA) 1 5.6 400 300 200 400 300 200 100 100 CIN = COUT = 1μF, VIN = 5.5V CIN = COUT = 1μF 0 0 2.8 3.45 4.1 4.75 5.4 Input Voltage (V) DS9718-02 May 2011 6.05 6.7 -50 -25 0 25 50 75 100 125 Temperature (°C) www.richtek.com 5 RT9718 Shutdown Current vs. Temperature 200 175 175 Shutdown Current (µA)1 Shutdown Current (µA)1 Shutdown Current vs. Input Voltage 200 150 125 100 75 50 150 125 100 75 50 25 25 CIN = COUT = 1μF 0 2.8 3.45 4.1 4.75 5.4 6.05 CIN = COUT = 1μF, VIN = 5.5V 0 -50 6.7 -25 0 25 50 75 Input Voltage (V) Temperature (°C) EN Threshold Voltage vs. Input Voltage Power On 100 125 EN Threshold Voltage (V) 1.20 Logic High 1.16 VIN (5V/Div) 1.12 VOUT (5V/Div) Logic Low 1.08 1.04 CIN = COUT = 1μF WRN (5V/Div) I IN (500mA/Div) CIN = COUT = 1μF 1.00 4.5 4.8 5.1 5.4 5.7 6 6.3 6.6 Time (2.5ms/Div) 6.9 Input Voltage (V) Input OVP Power Off VIN (5V/Div) VIN (10V/Div) VOUT (10V/Div) VOUT (5V/Div) WRN (10V/Div) WRN (5V/Div) IOUT (500mA/Div) IOUT (500mA/Div) CIN = COUT = 1μF Time (1ms/Div) www.richtek.com 6 CIN = COUT = 1μF Time (2.5ms/Div) DS9718-02 May 2011 RT9718 OCP Battery OVP VBATT VIN (5V/Div) VOUT (10V/Div) VBATT (2V/Div) VOUT (5V/Div) WRN (5V/Div) WRN (10V/Div) IOUT (1A/Div) IOUT (500mA/Div) CIN = COUT = 1μF, VIN = 5.5V Time (100ms/Div) DS9718-02 May 2011 CIN = COUT = 1μF, VIN = 5.5V Time (1ms/Div) www.richtek.com 7 RT9718 Applications Information Power Up Battery Over Voltage Protection The RT9718 has a threshold of 2.7V power on reset (POR) with a built-in hysteresis of 100mV. Before the input voltage reaches the POR threshold, the RT9718 is off. When the input voltage is over the POR threshold; the RT9718 will delay for 8ms and the soft-start will be activated after the 8ms delay. The 8ms delay allows any transients at the input during a hot insertion of the power supply to settle down before the IC starts to operate. The battery OVP threshold voltage is set at 4.35V in typical and the RT9718 has a built-in 180us blanking time to prevent any transient voltage from triggering the battery OVP. If the OVP situation still exists after 180us, the internal MOSFET will be turned off and the WRN pin indicates a LOW signal. The battery OVP threshold has a 30mV builtin hysteresis. The control logic contains a 4-bit binary counter. If the battery over voltage event occurs for consecutive 16 times, the MOSFET will be turned off permanently unless the input power or the enable pin is reset. During the soft-start transition, the RT9718 slowly turns on the internal MOSFET to reduce the inrush current. Enable Control The RT9718 offers an enable (EN) input. When the EN pin is pulled to logic high (>1.5V), the RT9718 will be shut down. When the EN pin is pulled to logic low (