TD1469

Techcode® DATASHEET 40V, 800MA, 1.2MHz synchronous Buck Converter TD1469 TD8325 General Description Features TD1469 is a 800mA synchronous buck converter with integrated power MOSFETs. The TD1469 design with a current-mode control scheme, can convert wide input voltage of 7V to 40V to the output voltage adjustable from 0.8V to 90%VIN to provide excellent output voltage regulation. The TD1469 equipped with Power-on-reset, soft start and whole protections (under-voltage, over temperature and current-limit) into a single package. This device, available SOT-23-6 provides a very compact system solution of external components and PCB area.               Wide Input Voltage from 7V to 40V 800mA Output Current High Efficiency over 85% from Load Current 50mA to 100mA @ VOUT>=5V Low EMI Converter Adjustable Output Voltage from 0.8V to 90%VIN Integrated High/Low Side MOSFET 1.2M Switching Frequency Stable with Low ESR Capacitors Power-On-Reset Detection Over-Temperature Protection Current-Limit Protection Enable/Shutdown Function Available in SOT-23-6 packages Lead Free and Green Devices Available (RoHS compliant). Applications  Smart Electronic equipments Output current(mA) Pin Configurations Package Types SOT23-6 June 30, 2020. (Top view) Techcode Semiconductor Limited 1 www.techcodesemi.com Techcode® DATASHEET 40V, 800MA, 1.2MHz synchronous Buck Converter TD1469 TD8325 Pin Description Pin Number Pin Name 1 BS 2 GDN Description High-Side Gate Drive Boost Input. BS supplies the voltage to drive the high-side N-channel MOSFET. At least 10nF capacitor should be connected from SW to BS to supply the high side switch. Signal and power ground. 3 FB Output feedback Input. The TD1469 senses the feedback voltage via FB and regulates the voltage at 0.8V. Connecting FB with a resistor-divider from the converter’s output sets the output voltage from 0.8V to 90%VIN. 4 EN Enable Input. EN is a digital input that turns the regulator on or off. EN threshold is 1.1V with 0.2V hysteresis. Pull up with 1MΩ resistor for automatic startup. 5 VIN Power Input. VIN supplies the power (7V to 40V) to the control circuitry, gate drivers and step-down converter switches. Connecting a ceramic bypass capacitor and a suitably large capacitor between VIN and GND eliminates switching noise and voltage ripple on the input to the IC. 6 SW Power Switching Output. It is the Drain of the N-Channel power MOSFET to supply power to the output LC filter. Ordering Information TD1469 □ Circuit Type Packing: Blank：Tube R: Tape and Reel Package T：SOT23-6 June 30, 2020. □ Techcode Semiconductor Limited 2 www.techcodesemi.com Techcode® DATASHEET 40V, 800MA, 1.2MHz synchronous Buck Converter TD1469 TD8325 Function Block Figure1 Function Block Diagram of TD1469 June 30, 2020. Techcode Semiconductor Limited 3 www.techcodesemi.com Techcode® DATASHEET 40V, 800MA, 1.2MHz synchronous Buck Converter TD1469 TD8325 Absolute Maximum Ratings (Note1) Symbol Parameter Rating Unit VIN VIN Supply Voltage（VIN to Gnd） -0.3 ~ 43 V VSW SW to GND Voltage -0.3 to VIN+0.3 V VBS BS to GND Voltage VSW - 0.3 ~ VSW +6 V All Other Pins PD Power Dissipation TJ Junction Temperature TSTG Storage Temperature TSDR -0.3 ~ 6 V Internally Limited ºC 150 ºC -65 ~ 150 Maximum Lead Soldering Temperature (10 Seconds) W ºC 260 Note1: 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 under "recommended operating conditions" is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Thermal Characteristics Symbol θJA Parameter Junction-to-Ambient Resistance in free air (Note 2) SOT-23-6 Typical Value Unit 250 °C/W Note 2: θJA is measured with the component mounted on a high effective thermal conductivity test board in free air. Recommended Operation Conditions (Note3) Symbol Parameter Range VIN VIN Supply Voltage VOUT Converter Output Voltage VFB ~ VIN*90% Operating Junction Temp -40 ~ 125 7 ~ 40 Unit V V o C Note 3: Refer to the typical application circuit June 30, 2020. Techcode Semiconductor Limited 4 www.techcodesemi.com Techcode® DATASHEET 40V, 800MA, 1.2MHz synchronous Buck Converter TD1469 TD8325 Electrical Characteristics Unless otherwise specified, these specifications apply over VIN=12V, VEN=3V and TA = 25ºC. Symbol Parameter Test Conditions Min Typ 0.792 0.812 0.832 V - - 0.1 µA High Side MOSFET Resistance - 0.9 - Ω Low Side MOSFET Resistance - 0.4 - Ω - - 1 µA - 1 - A 0.96 1.2 1.44 MHZ VFB Feedback Voltage 10V ≤ VIN ≤ 60V IFB Feedback Current VFB = 0.85V RDS(ON) ISW_LKG Switch Leakage VEN=0V,VSW=0V Max Unit ILIM Current Limit fSW Oscillator Frequency VFB=0.6V fSW_F Foldback Frequency VFB=0V - 125 - KHZ DMAX Maximum Duty Cycle VFB=0.6V - 90 - % TON Minimum ON-Time - 100 - ns VUVLO_R Under-Voltage Lockout Threshold, Rising - 6 - V VUVLO_F Under-Voltage Lockout Threshold, Falling - 5.5 - V VUVLO_HYS Under-Voltage Lockout Threshold,Hysteresis - 0.5 - V Soft Start Time - 1 - ms VEN_R EN Threshold, Rising - 1.1 - V VEN_F EN Threshold, Falling - 0.9 - V EN Threshold, Hysteresis - 200 - mv VEN=2V - 3.1 - µA VEN=0V - 0.1 - µA tSS VEN_HYS IEN EN Input Current IS Supply Current (Shutdown) VEN=0V - 0.1 1 µA IQ Supply Current (Quiescent) VEN=2V,VFB=1V - 0.73 0.85 mA TSD Thermal Shutdown - 165 - o - o TSD_HYS - Thermal Shutdown Hysteresis June 30, 2020. Techcode Semiconductor Limited 5 20 C C www.techcodesemi.com Techcode® DATASHEET 40V, 800MA, 1.2MHz synchronous Buck Converter TD1469 TD8325 Typical Application Circuit U1 5 VIN C1 10uF VIN BST SW R3 1M 1 C3 0.1uF 6 L1 22uH 5V VOUT TD1469 C2 22uF EN FB 3 R2 8.2K 2 4 GND R1 43K = June 30, 2020. ( + ) Techcode Semiconductor Limited 6 www.techcodesemi.com Techcode® DATASHEET 40V, 800MA, 1.2MHz synchronous Buck Converter TD1469 TD8325 Application Information Main Control Loop The TD1469 is a constant frequency, synchronous rectifier and current-mode switching regulator. In normal operation, the internal upper power MOSFET is turned on each cycle. The peak inductor current at which ICMP turn off the upper MOSFET is controlled by the voltage on the COMP node, which is the output of the error amplifier(EAMP). An external resistive divider connected between Vout and ground allows the EAMP to receive an output feedback voltage VFB at FB pin. When the load current increases, it causes a slightly decrease in VFB relative to the 0.8V reference, which in turn causes the COMP voltage to increase until the average inductor current matches the new load current. Setting Output Voltage The regulated output voltage is determined by: R VOUT = 0.8 × (1 + ) R VIN Power-On-Reset (POR) The TD1469 keep monitoring the voltage on VIN pin to prevent wrong logic operations which may occur when VIN voltage is not high enough for the internal control circuitry to operate. The VIN POR has a rising threshold of 6V (typical) with 0.5V of hysteresis. After the VIN voltages exceed its respective POR thresholds, the IC starts a start-up process and then ramps up the output voltage to the setting of output voltage. Connect a RC network from EN to GND to set a turn-on delay that can be used to sequence the output voltages of multiple devices. Over-Current-Protection and Hiccup The TD1469 has a cycle-by-cycle over-current limit when the inductor current peak value exceeds the set current limit threshold. Meanwhile, the output voltage drops until FB is below the Under-Voltage (UV) threshold below the reference. Once UV is triggered, the TD1469 enters hiccup mode to periodically restart the part. This protection mode is especially useful when the output is dead-shorted to ground. The average short circuit current is greatly reduced to alleviate thermal issues and to protect the regulator. The TD1469 exits the hiccup mode once the over-current condition is removed. Enable/Shutdown Driving EN to ground places the TD1469 in shutdown. When in shutdown, the internal power MOSFETes turn off, all internal circuitry shuts down and the quiescent supply current of VlN reduces to