TD1663

Techcode® DATASHEET 60V, 3A, Step-Down Converter TD1663 General Description Features The TD1663 is a 60V, 3A step down regulator with an integrated high-side MOSFET. With a wide input range from 9V to 60V, it’s suitable for various applications from industrial to automotive for power conditioning from unregulated sources. An ultra-low 1μA current in shutdown mode can further prolong battery life. Internal loop compensation means that the user is free from the tedious task of loop compensation design. This also minimizes the external components of the device. A precision enable input allows simplification of regulator control and system power sequencing. The device also has built-in protection features such as cycle-by-cycle current limit, thermal sensing and shutdown due to excessive power dissipation, and output overvoltage protection. The TD1663 is available in a ESOP-8 package.          9V to 60V Input Range 3A Continuous Output Current 150 mΩ High-Side MOSFET Current Mode Control Adjustable Switching Frequency from 200kHz to 1 MHz Internal Compensation for Ease of Use 1 μA Shutdown Current Thermal, Overvoltage and Short Protection Available in a ESOP-8 Package Applications     Automotive Battery Regulation Industrial Power Supplies Telecom and Datacom Systems General Purpose Wide Vin Regulation Pin Configurations (Top view) May 13, 2020. Techcode Semiconductor Limited 1 www.techcodesemi.com Techcode® DATASHEET 60V, 3A, Step-Down Converter TD1663 Pin Description Pin Number Pin Name Description Bootstrap capacitor connection for high-side MOSFET driver. Connect a high quality 0.1μF capacitor from BOOT to SW. 1 BOOT 2 VIN Connect to power supply and bypass capacitors CIN. Path from VIN pin to high frequency bypass CIN and GND must be as short as possible. 3 EN Enable pin, with internal pull-up current source. Pull below 1.2V to disable. Float or connect to VIN to enable. Adjust the input under voltage lockout with two resistors. See the Enable and Adjusting Under voltage lockout section. 4 RT Resistor Timing. An internal amplifier holds this pin at a fixed voltage when using an external resistor to ground to set the switching frequency. 5 FB Feedback input pin, connect to the feedback divider to set VOUT. Do not short this pin to ground during operation. 6 PGOOD Power-Good pin, open drain output for power-good flag, use a 10 kΩ to 100 kΩ pull-up resistor to logic rail or other DC voltage no higher than 7 V. 7 GND System ground pin. 8 SW Switching output of the regulator. Internally connected to high-side power MOSFET. Connect to power inductor. 9 Thermal Pad Major heat dissipation path of the die. Must be connected to ground plane on PCB. Ordering Information TD1663 □ □ Circuit Type Packing: Blank：Tube R: Tape and Reel M: ESOP-8 May 13, 2020. Techcode Semiconductor Limited 2 www.techcodesemi.com Techcode® DATASHEET 60V, 3A, Step-Down Converter TD1663 Function Block Figure1 Function Block Diagram of TD1663 Absolute Maximum Ratings (Note1) Rating Input Voltages May 13, 2020. VIN to GND -0.3 to 65 EN to GND -0.3 to 5 PGOOD to GND -0.3 to 5 FB to GND -0.3 to 7 Techcode Semiconductor Limited 3 Unit V www.techcodesemi.com Techcode® DATASHEET 60V, 3A, Step-Down Converter Output Voltages TD1663 BOOT to SW 6.5 SW to GND -0.3 to VIN+0.3 V TJ Junction Temperature 150 ºC TSTG Storage Temperature -65 ~ 150 ºC 260 ºC TSDR Maximum Lead Soldering Temperature (10 Seconds) 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. ESD Ratings V(ESD) Electrostatic discharge Human-boody model(HBM) VALUE UNIT +2000 V Recommended Operation Conditions Range Unit VIN 9 to 60 VOUT 0.8 to 50 SW -1 to 60 FB 0 to 5 Frequency Switching frequency range 200 to 1000 kHz Temperature Operating junction temperature, TJ -40 to 125 ℃ Buck Regulator V Operating Ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications, see Electrical Characteristics . May 13, 2020. Techcode Semiconductor Limited 4 www.techcodesemi.com Techcode® DATASHEET 60V, 3A, Step-Down Converter TD1663 Electrical Characteristics Limits apply over the recommended operating junction temperature (TJ) range of -40 °C to +125 °C, unless otherwise stated. Minimum and Maximum limits are specified through test, design or statistical correlation. Typical values represent the most likely parametric norm at TJ = 25 °C, and are provided for reference purposes only. Unless otherwise specified, the following conditions apply: VIN = 9 V to 60 V. Symbol VIN Parameter Test Conditions Operation input voltage Min Typ Max Unit 9 - 60 V UVLO Under voltage lockout thresholds Rising threshold - 8.5 - V Hysteresis - 1.4 - V ISHDN Shutdown supply current VEN = 0V, TA = 25°C, 9V≤VIN≤60V - 1.0 3.0 µA Operating quiescent current (non-switching) VFB = 1.0V, TA = 25°C - 200 - µA - 2 - V - 4 - ms 0.735 0.750 0.765 V - 150 - mΩ 3.80 4.75 5.70 A IQ ENABLE (EN PIN) VEN_TH EN Threshold Voltage SOFT-START TSS Internal soft-start time 10% to 90% of FB voltage VOLTAGE REFERENCE (FB PIN) VFB Feedback voltage TJ = 25 °C HIGH-SIDE MOSFET RDS_ON On-resistance VIN = 12 V, BOOT to SW = 5.8 V HIGH-SIDE MOSFET CURRENT LIMIT ILIMT Current limit VIN = 12 V, TA = 25 °C, Open Loop THERMAL PERFORMANCE TSHDN Thermal shutdown threshold - 150 - THYS Hysteresis - 12 - Min Typ Max Unit 400 500 600 kHz ℃ Switching Characteristics Over the recommended operating junction temperature range of -40 °C to 125 °C (unless otherwise noted) Symbol Parameter Test Conditions fSW Switching frequency RT = 49.9 kΩ TON_MIN Minimum controllable on time VIN = 12 V, BOOT to SW = 5.8 V, ILoad =1 A - 160 - ns DMAX Maximum duty cycle fSW = 500 kHz - 90% - - May 13, 2020. Techcode Semiconductor Limited 5 www.techcodesemi.com Techcode® DATASHEET 60V, 3A, Step-Down Converter TD1663 Typical Application Circuit C4 U1 0.1uF L1 10uH 1 2 VIN BST SW 8 VOUT VIN D1 SB560 R3 1M C2 22uF C3 22uF TD1663 EC1 R2 68K R4 49.9K PGOOD RT FB 5 R1 12K 6 4 EN GND 3 7 100uF C1 1uF R5 100K Figure2 Application Circuit, 5V Output May 13, 2020. Techcode Semiconductor Limited 6 www.techcodesemi.com Techcode® DATASHEET 60V, 3A, Step-Down Converter TD1663 Function Description Fixed Frequency Peak Current Mode Control TD1663 output voltage is regulated by turning on the high-side N-MOSFET with controlled ON time. During high-side switch ON time, the SW pin voltage swings up to approximately VIN, and the inductor current iL increase with linear slope (VIN – VOUT) / L. When high-side switch is off, inductor current discharges through freewheel diode with a slope of –VOUT / L. The control parameter of Buck converter is defined as Duty Cycle D = tON / TSW, where tON is the high-side switch ON time and TSW is the switching period. The regulator control loop maintains a constant output voltage by adjusting the duty cycle D. In an ideal Buck converter, where losses are ignored, D is proportional to the output voltage and inversely proportional to the input voltage: D = VOUT / VIN. The TD1663 employs fixed frequency peak current mode control. A voltage feedback loop is used to get accurate DC voltage regulation by adjusting the peak current command based on voltage offset. The peak inductor current is sensed from the high-side switch and compared to the peak current to control the ON time of the high-side switch. The voltage feedback loop is internally compensated, which allows for fewer external components, makes it easy to design, and provides stable operation with almost any combination of output capacitors. The regulator operates with fixed switching frequency at normal load condition. At very light load, the TD1663 will operate in Sleep-mode to maintain high efficiency and the switching frequency will decrease with reduced load current. Slope Compensation The TD1663 adds a compensating ramp to the MOSFET switch current sense signal. This slope compensation prevents sub-harmonic oscillations at duty cycles greater than 50%. The peak current limit of the high-side switch is not affected by the slope compensation and remains constant over the full duty cycle range. Low Dropout Operation and Bootstrap Voltage (BOOT) The TD1663 provides an integrated bootstrap voltage regulator. A small capacitor between the BOOT and SW pins provides the gate drive voltage for the high-side MOSFET. The BOOT capacitor is refreshed when the high-side MOSFET is off and the external low side diode conducts. The recommended value of the BOOT capacitor is 0.1 μF. A ceramic capacitor with an X7R or X5R grade dielectric with a voltage rating of 16 V or greater is recommended for stable performance over temperature and voltage. When operating with a low voltage difference from input to output, the high-side MOSFET of the TD1663 will operate at approximate 95% duty cycle. When the voltage from BOOT to SW drops below 3.2 V, the high-side MOSFET is turned off and an integrated low side MOSFET pulls SW low to recharge the BOOT capacitor. Since the gate drive current sourced from the BOOT capacitor is small, the high-side MOSFET can remain on for many switching cycles before the MOSFET is turned off to refresh the capacitor. Thus the effective duty cycle of the switching regulator can be high, approaching 95%. The effective duty cycle of the converter during dropout is mainly influenced by the voltage drops across the power MOSFET, the inductor resistance, the low side diode voltage and the printed circuit board resistance. Adjustable Output Voltage The internal voltage reference produces a precise 0.75 V (typical) voltage reference over the operating temperature range. The output voltage is set by a resistor divider from output voltage to the FB pin. It is recommended to use 1% tolerance or better and temperature coefficient of 100 ppm or less divider resistors. Select the low side resistor RFBB for the desired divider current and use Equation 1 to calculate high-side RFBT. Larger value divider resistors are good for efficiency at light load. However, if the values are too high, the regulator will be more susceptible to noise and voltage errors from the FB input current may become noticeable. RFBB in the range from 10 kΩ May 13, 2020. Techcode Semiconductor Limited 7 www.techcodesemi.com Techcode® DATASHEET 60V, 3A, Step-Down Converter TD1663 to 100 kΩ is recommended for most applications. Enable and Adjustable Under-voltage Lockout The TD1663 is enabled when the VIN pin voltage rises above 8.5 V (typical) and the EN pin voltage exceeds the enable threshold of 2 V (typical). The TD1663 is disabled when the VIN pin voltage falls below 7 V (typical) or when the EN pin voltage is below 2 V. Switching Frequency and Synchronization (RT/SYNC) The switching frequency of the TD1663 can be programmed by the resistor RT from the RT pin and GND pin. The RT pin can’t be left floating or shorted to ground. To determine the timing resistance for a given switching frequency(200kHz-1MHz), use the below Equation: Power Good (PGOOD) The TD1663 has a built in power-good flag shown on PGOOD pin to indicate whether the output voltage is within its regulation level. The PGOOD signal can be used for start-up sequencing of multiple rails or fault protection. The PGOOD pin is an open-drain output that requires a pull-up resistor to an appropriate DC voltage. Voltage seen by the PGOOD pin should never exceed 7V. A resistor divider pair can be used to divide the voltage down from a higher potential. A typical range of pull-up resistor value is 10kΩ to 100kΩ. When the FB voltage is within the power-good band, +7% above and -6% below the internal reference VREF typically, the PGOOD switch will be turned off and the PGOOD voltage will be pulled up to the voltage level defined by the pull-up resistor or divider. When the FB voltage is outside of the tolerance band, +9% above or -8% below VREF typically, the PGOOD switch will be turned on and the PGOOD pin voltage will be pulled low to indicate power bad. Over Current and Short Circuit Protection The TD1663 is protected from over current condition by cycle-by-cycle current limiting on the peak current of the high-side MOSFET. High-side MOSFET over-current protection is implemented by the nature of the Peak Current Mode control. The high-side switch current is compared to the output of the Error Amplifier (EA) minus slope compensation every switching cycle. Please refer to Functional Block Diagram for more details. The peak current of high-side switch is limited by a clamped maximum peak current threshold which is constant. So the peak current limit of the high-side switch is not affected by the slope compensation and remains constant over the full duty cycle range. May 13, 2020. Techcode Semiconductor Limited 8 www.techcodesemi.com Techcode® DATASHEET 60V, 3A, Step-Down Converter TD1663 The TD1663 also implements a frequency fold-back to protect the converter in severe over-current or short conditions. The frequency fold-back increases the off time by increasing the period of the switching cycle, so that it provides more time for the inductor current to ramp down and leads to a lower average inductor current. Lower frequency also means lower switching loss. Frequency fold-back reduces power dissipation and prevents overheating and potential damage to the device. Overvoltage Protection The TD1663 employs an output overvoltage protection (OVP) circuit to minimize voltage overshoot when recovering from output fault conditions or strong unload transients in designs with low output capacitance. The OVP feature minimizes output overshoot by turning off high-side switch immediately when FB voltage reaches to the rising OVP threshold which is nominally 109% of the internal voltage reference VREF. When the FB voltage drops below the falling OVP threshold which is nominally 107% of VREF, the high-side MOSFET resumes normal operation. Thermal Shutdown The TD1663 provides an internal thermal shutdown to protect the device when the junction temperature exceeds 150°C (typical). The high-side MOSFET stops switching when thermal shundown activates. Once the die temperature falls below 130°C (typical), the device reinitiates the power up sequence controlled by the internal soft-start circuitry. Shutdown Mode The EN pin provides electrical ON and OFF control for the TD1663. When VEN is below 1.0 V, the device is in shutdown mode. The switching regulator is turned off and the quiescent current drops to 1.0μA typically. The TD1663 also employs under voltage lock out protection. If VIN voltage is below the UVLO level, the regulator will be turned off. Light Load Operation When the load current is lower than half of the peak-to-peak inductor current in CCM, the TD1663 will operate in DCM. At even lighter current loads, Sleep-mode is activated to maintain high efficiency operation by reducing switching and gate drive losses. Layout Guidelines Layout is a critical portion of good power supply design. The following guidelines will help users design a PCB with the best power conversion performance, thermal performance, and minimized generation of unwanted EMI. 1. The feedback network, resistor RFBT and RFBB, should be kept close to the FB pin. VOUT sense path away from noisy nodes and preferably through a layer on the other side of a shielding layer. 2. The input bypass capacitor CIN must be placed as close as possible to the VIN pin and ground. Grounding for both the input and output capacitors should consist of localized top side planes that connect to the GND pin and PAD. 3. The inductor L should be placed close to the SW pin to reduce magnetic and electrostatic noise. 4. The output capacitor, COUT should be placed close to the junction of L and the diode D. The L, D, and COUT trace should be as short as possible to reduce conducted and radiated noise and increase overall efficiency. 5. The ground connection for the diode, CIN, and COUT should be as small as possible and tied to the system ground plane in only one spot (preferably at the COUT ground point) to minimize conducted noise in the system ground plane. . May 13, 2020. Techcode Semiconductor Limited 9 www.techcodesemi.com Techcode® DATASHEET 60V, 3A, Step-Down Converter TD1663 Package Information ESOP-8 Package Outline Dimensions May 13, 2020. Techcode Semiconductor Limited 10 www.techcodesemi.com Techcode® DATASHEET 60V, 3A, Step-Down Converter TD1663 Design Notes May 13, 2020. Techcode Semiconductor Limited 11 www.techcodesemi.com