RT9709AGQWB

RT9709 Integrated Over Voltage Protection Circuit General Description Features The RT9709 is an integrated circuit (IC) optimized to protect low voltage system from abnormal high voltage input 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. It also monitors its own temperature and turns the MOSFET off when the chip temperature exceeds 140°C. z The RT9709 can support AC charger or USB charger. When the input voltage exceeds the OVP threshold, the IC turns off the MOSFET within 1us to remove the power before any damage occurs. The IC also monitors the battery voltage VB. When the battery voltage exceeds 4.4V and last for more than 180us the RT9709 will turn off the MOSFET. The internal logic control will turn off and latch the MOSFET when the battery over-voltage event reaches 16 times. User Programmable OCP Threshold ` Input OVP Less than 1us ` Battery OVP Up to 30V Over Voltage Protection High Accuracy Protection Threshold High Immunity of False Triggering Under Transients Warning Indication Output Enable Input Thermally Enhanced WDFN Package RoHS Compliant and Halogen Free ` z z z z z z z The current in the 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 has a 4-bit binary counter that accumulates during an OCP event. When the total count reaches 16 times, the MOSFET will be turned off permanently unless the input power is recycled. Fully Integrated Protection Circuit for Three Protection Variables Applications z z z z Cellular Phones Digital Cameras PDAs and Smart Phones Portable Instruments Ordering Information RT9709 Package Type QW : WDFN-12L 4x3 (W-Type) QWB : WDFN-10L 3x3 (W-Type) Lead Plating System G : Green (Halogen Free and Pb Free) OVP Default : 6.8V A : 5.85V B : 6.25V Pin Configurations (TOP VIEW) VIN VIN GND WRN NC NC 12 NC 11 VOUT 1 2 3 4 5 6 GND 13 10 VOUT 9 ILIM 8 7 VB EN Note : Richtek products are : ` RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. WDFN-12L 4x3 WRN 4 NC 5 10 VOUT 9 VOUT GND 11 8 ILIM 7 VB 9 VIN 1 VIN 2 GND 3 ` EN Suitable for use in SnPb or Pb-free soldering processes. Marking Information For marking information, contact our sales representative directly or through a Richtek distributor located in your area. WDFN-10L 3x3 DS9709-02 April 2011 www.richtek.com 1 RT9709 Typical Application Circuit RT9709/A/B VIN CIN WRN VIN VOUT VIN VOUT GND VB WRN ILIM EN NC Charger RVB EN + Battery RILIMIT Functional Pin Description Pin No. Pin Name Pin Function WDFN-12L 4x3 WDFN-10L 3x3 1, 2 1, 2 VIN Input Power Source Pin. 3 3 GND Ground Pin. 4 4 WRN 5, 6, 12 5 NC No Internal Connection. 7 6 EN Enable Input Pin. Pull this pin to low or leave it floating to enable the IC. Force this pin to high to disable the IC. 8 7 VB Battery Voltage Monitoring Input Pin. This pin is connected to the battery pack positive terminal via resistor. 9 8 ILIM Over-Current Protection Threshold Setting Pin. Connect a resistor between this pin and GND to set the OCP threshold. 10, 11 9, 10 VOUT Output Voltage Pin. Output through the MOSFET. This is an open-drain logic output that turns LOW when any protection event occurs. The exposed pad must be soldered to a large PCB and connected to GND for maximum thermal dissipation. 13 (Expose Pad) 11 (Exposed 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 DS9709-02 April 2011 RT9709 Absolute Maximum Ratings z z z z z z z z z (Note 1) Supply Input Voltage, VIN -------------------------------------------------------------------------------------------- −0.3V to 30V VOUT, VB --------------------------------------------------------------------------------------------------------------- −0.3V to 7V Other Pins --------------------------------------------------------------------------------------------------------------- −0.3V to 5.5V Power Dissipation, PD @ TA = 25°C WDFN-10L 3x3 --------------------------------------------------------------------------------------------------------- 1.429W WDFN-12L 4x3 --------------------------------------------------------------------------------------------------------- 1.667W Package Thermal Resistance (Note 2) WDFN-10L 3x3, θJA --------------------------------------------------------------------------------------------------- 70°C/W WDFN-10L 3x3, θJC --------------------------------------------------------------------------------------------------- 7°C/W WDFN-12L 4x3, θJA --------------------------------------------------------------------------------------------------- 60°C/W WDFN-12L 4x3, θJC --------------------------------------------------------------------------------------------------- 7°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) ------------------------------------------------------------------------------------------ 3kV MM (Machine Mode) -------------------------------------------------------------------------------------------------- 250V 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, CIN = 1uF, TA = 25°C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Units 4.3 -- 6.5 V 4.3 -- 5.5 V 4.3 -- 5.9 V V IN Rising 2.4 2.6 2.7 V Hysteresis -- 100 -- mV Power- On Reset RT9709 Operation Voltage RT9709A VIN RT9709B Under Voltage Lockout Threshold VUVLO Quiescent Current IQ When Enable, VEN < 0.4V -- 0.5 1 mA Shutdown Current IQ_SD When Disable, VEN > 1.5V 30 60 100 uA 6.65 6.8 7.0 V 5.65 5.85 6.0 V 6 6.25 6.5 V Protections Input OVP Reference Voltage RT9709 RT9709A VOVP RT9709B Input OVP Hysteresis Input OVP Propagation Delay Over Current Protection Over Current Protection Blanking Time V OUT = VIN x 80% IOCP BT OCP -- 60 100 mV -- -- 1 us 0.93 1 1.07 A -- 170 -- us To be continued DS9709-02 April 2011 www.richtek.com 3 RT9709 Parameter Symbol Battery Over Voltage Protection VBOVP Battery OVP Blanking time BTOVP VB Pin Leakage Current OTP Threshold Test Conditions Min Typ Max Units Threshold 4.3 4.35 4.4 V Hysteresis -- 30 -- mV -- 180 -- us -- -- 100 nA Rising -- 140 -- °C Falling -- 90 -- °C VVB = 4.4V T SD Logic EN/ Threshold Logic-High Voltage V IH 1.5 -- -- V Logic-Low Voltage V IL -- -- 0.4 V 100 200 400 kΩ -- 0.35 0.8 V -- -- 1 uA -- 200 400 mΩ EN/ Internal Pull Down Resistor WRN/ Output Logic Low Sink 5mA WRN Output Logic High Leakage Current Power MOSFET On Resistance (P-MOSFET) RON1 IOUT = 500mA, 4.3V < V IN < 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 high effective four layers thermal conductivity test board of JEDEC 51-7 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 DS9709-02 April 2011 RT9709 Typical Operating Characteristics Power On from VIN Power Off from VIN VIN (5V/Div) VIN (5V/Div) VOUT (5V/Div) VOUT (5V/Div) WRN (2V/Div) WRN (2V/Div) IOUT (500mA/Div) CIN = COUT = 1uF CIN = COUT = 1uF Time (2.5ms/Div) Time (250us/Div) Input OVP OCP VIN (10V/Div) VIN (5V/Div) VOUT (10V/Div) VOUT (5V/Div) WRN (2V/Div) WRN (5V/Div) IOUT (1A/Div) IOUT (1A/Div) CIN = COUT = 1uF VIN = 5.5V, CIN = COUT = 1uF Time (100ms/Div) Time (100ms/Div) Battery OVP Quiescent Current vs. Input Voltage 600 500 Quiescent Current (uA) VACIN (5V/Div) VBATT (5V/Div) WRN (2V/Div) IOUT (500mA/Div) CIN = COUT = 1uF Enable 400 300 200 100 Disable VIN = 5.5V, CIN = COUT = 1uF 0 Time (100ms/Div) 2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5 5.8 6.1 6.4 6.7 Input Voltage (V) DS9709-02 April 2011 www.richtek.com 5 RT9709 Quiescent Current vs. Temperature 700 VIN = 5.5V, CIN = COUT = 1uF RSET = 25kΩ, CIN = COUT = 1uF Enable Current 600 1.03 OCP Threshold (A) Quiescent Current (uA) OCP Threshold vs. Inputt Voltage 1.05 500 400 300 200 1.01 0.99 0.97 Disable Current 100 0 0.95 -40 -20 0 20 40 60 80 100 120 4.4 4.7 5 5.3 Temperature (°C) VIN = 5.5V, RSET = 25kΩ, CIN = COUT = 1uF Battery OVP Threshold (V) OCP Threshold (A) 4.40 1.03 1.01 0.99 0.97 -40 6.5 6.8 CIN = COUT = 1uF 4.38 4.35 4.33 4.30 4.28 4.25 4.23 -20 0 20 40 60 80 100 4.5 120 4.75 5 5.25 5.5 5.75 6 6.25 6.5 6.75 Input Voltage (V) Temperature (°C) EN Threshold Voltage vs. Input Voltage Battery OVP Threshold vs. Temperature 0.95 VIN = 5.5V, CIN = COUT = 1uF CIN = COUT = 1uF 0.94 4.38 EN Threshold Voltage (V) Battery OVP Threshold (V) 6.2 4.20 0.95 4.40 5.9 Battery OVP Threshold vs. Input Voltage OCP Threshold vs. Temperature 1.05 5.6 Inputt Voltage (V) 4.35 4.33 4.30 4.28 4.25 4.23 0.93 Rising 0.92 Falling 0.91 0.90 0.89 0.88 0.87 0.86 0.85 4.20 -40 -20 0 20 40 60 80 Temperature (°C) www.richtek.com 6 100 120 4.5 4.75 5 5.25 5.5 5.75 6 6.25 6.5 6.75 Input Voltage (V) DS9709-02 April 2011 RT9709 RDS(ON) vs. Input Voltage Input OVP Threshold vs. Temperature 6.80 0.29 CIN = COUT = 1uF CIN = COUT = 1uF 0.27 6.78 0.25 6.77 R DS(ON) (Π ) DS(ON) (Ω) Input OVP Threshold (V) 6.79 6.76 6.75 6.74 6.73 0.23 0.21 0.19 6.72 0.17 6.71 0.15 6.70 -40 -20 0 20 40 60 80 100 120 4.3 4.5 4.7 4.9 5.1 5.3 5.5 5.7 5.9 6.1 6.3 6.5 6.7 Input Voltage (V) Temperature (°C) RDS(ON) vs. Temperature 0.45 VIN = 5.5V, CIN = COUT = 1uF 0.40 R DS(ON) (Ω) (Π ) 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 -40 -20 0 20 40 60 80 100 120 Temperature (°C) DS9709-02 April 2011 www.richtek.com 7 RT9709 Applications Information Power Up The RT9709 has an input under voltage lockout (UVLO) threshold of 2.6V with a built-in hysteresis of 100mV. Before the input voltage reaches the UVLO threshold, the RT9709 is off. When the input voltage is over the UVLO threshold; the RT9709 will delay for 10ms and after the 10ms delay, the soft-start will be activated. The 10ms delay allows any transients at the input during a hot insertion of the power supply to settle down before the IC starts to operate. During the soft-start transition, the RT9709 slowly turns on the internal MOSFET to reduce the inrush current. Enable Control The RT9709 offers an enable (EN) input. When the EN pin is pulled to logic high (>1.5V), the RT9709 will be shut down. When the EN pin is pulled to logic low (