TD1432PR

Techcode® DATASHEET TD1432 2A 150KHz PWM Buck DC/DC Converter General Description Features TD1432 is a monolithic asynchronous buck regulator. The device provides 2A of continuous load current over a wide input voltage of 9V to 40V. It uses current mode control to regulator the output voltage and provides fast transient response. Requiring a minimum number of external components, these regulators are simple to use and include internal frequency compensation, and a fixed-frequency oscillator. Anti-ring function is to reduce the influence of EMI. This device, available in a SOP-8 package, provides a very compact system solution with minimal reliance on external components. ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ Internal Power MOSFET 2A continuous output current Up to 90% efficiency Input voltage range: 9V to 40V Fixed 150kHz frequency internal oscillator Current limit protection Anti-ringing for lower EMI Over temperature protection SOP-8 package Applications ⚫ ⚫ ⚫ ⚫ ⚫ Simple high-efficiency step-down regulator Efficient pre-regulator for linear regulators On-card switching regulators Positive to negative converter Battery charger Pin Configurations VIN 1 SW 2 FB ON/OFF 8 GND 7 GND 3 6 GND 4 5 GND TD1432 Figure1 Pin Configuration of TD1432(Top View) April 1, 2022. Techcode Semiconductor Limited 1 www.techcodesemi.com Techcode® DATASHEET TD1432 2A 150KHz PWM Buck DC/DC Converter Pin Description Pin Number Pin Name Description 1 VIN Power Input. In supplies the power to the IC, as well as the step-down converter switches. Drive IN with a 9V to 40V power source. Bypass IN to GND with a suitably large capacitor to eliminate noise on the input to the IC. See Input Capacitor. 2 SW Power Switching Output. SW is the switching node that supplies power to the output. Connect the output LC filter from SW to the output load. 3 FB Feedback Input. FB senses the output voltage to regulate that voltage. Drive FB with a resistive voltage divider from the output voltage. The feedback threshold is 1.23V. 4 ON/OFF Enable Input. ON/OFF is a digital input that turns the regulator on or off. Diver ON/OFF low to turn on the regulator; drive it high to turn it off. Do not floating when Vin>32V. GND Ground. 5,6,7,8 Ordering Information TD1432 □ □ Circuit Type Output voltage: 5: 5V R: ADJ Package P: SOP8 April 1, 2022. Techcode Semiconductor Limited 2 www.techcodesemi.com Techcode® DATASHEET TD1432 2A 150KHz PWM Buck DC/DC Converter Function Block VIN ON/OFF Start up & Regulator Current Sense LDO Current Limit comp UVLO Power MOS Bandgap Control Logic& Driver Buffer OSC FB Vs Vref1 EA SW PWM comp Vcomp Anti-ringing Circuit R1 C1 EA Clamp Softstart Thermal Shutdown Short Circuit Protection Over Voltage Protection AGND Figure 2 Function Block Diagram of TD1432 Absolute Maximum Ratings Parameter Input Voltage Feedback Pin Voltage ON/OFF Pin Voltage Output Pin Voltage Power Dissipation Operating Junction Temperature Storage Temperature Lead Temperature ESD (HBM) MSL Thermal Resistance-Junction to Ambient Thermal Resistance-Junction to Case April 1, 2022. symbol VIN VFB VEN VSW PD TJ TSTG TLEAD RθJA RθJC Techcode Semiconductor Limited 3 Value -0.3 to 42 -0.3 to 5 -0.3 to 5 -0.3 to VIN+0.3 Internally limited 150 -65 to 150 260 2000 Level3 85 45 Unit V V V V mW ℃ ℃ ℃ V ℃/W ℃/W www.techcodesemi.com Techcode® DATASHEET TD1432 2A 150KHz PWM Buck DC/DC Converter Recommended Operating Conditions Parameter Input voltage Output voltage Converter output current Operating junction temperature Operating ambient temperature Symbol VIN Vout Iout TJ TA Min. 9 1.23 0 -40 -40 Max. 40 Unit V V A ℃ ℃ 2 125 85 Electrical Characteristics VIN =12V, TA =+25℃, unless otherwise noted Parameter Symbol Condition Min Typ Max Units TD1432PR VFB 9V≤VIN≤40V 1.200 1.23 1.26 V TD1432P5 VOUT 9V≤VIN≤40V ON/OFF=5V 4.8 5.0 5.2 V - - 10 uA IQ ON/OFF=0V; VFB=1.5V - 3 4.5 mA FOSC1 VFB>0.3 120 150 180 kHz - 400 - mΩ - 3.8 - A - - 98 % Shutdown Supply Current Quiescent current Oscillation Frequency Highside Switch On Resistance Current Limit Maximum Duty Cycle ON/OFF Threshold voltage RDS(ON) IL Peak output current DMAX VIL Low(Regulator ON) - 0.9 - V VIH High(Regulator OFF) - 1.0 - V VIN Rising - 8.3 - V Input Under Voltage Lockout Threshold Hysteresis - 500 - mV Thermal Shutdown - 160 - ℃ Input Under Voltage Lockout Threshold April 1, 2022. Techcode Semiconductor Limited 4 www.techcodesemi.com Techcode® DATASHEET TD1432 2A 150KHz PWM Buck DC/DC Converter Typical Application Circuit CFF R1 3.6K R2 11K 3 FB 47uH 1 DC IN Vin TD1432PR SW Cin1 220uf Cin2 0.1uf GND 5-8 5V 2 Cout 330uf D1 ON/OFF 4 SK34 DC LOAD Figure 3 Typical Application of TD1432PR 3 FB 47uH 1 DC IN Vin TD1432P5 SW Cin1 220uf Cin2 0.1uf GND 5-8 5V 2 ON/OFF 4 D1 SK34 Cout 330uf DC LOAD Figure 4 Typical Application of TD1432P5 April 1, 2022. Techcode Semiconductor Limited 5 www.techcodesemi.com Techcode® DATASHEET TD1432 2A 150KHz PWM Buck DC/DC Converter Function Description The TD1432 regulates input voltages from 9V to 40V down to an output voltage as low as 1.23V, and supplies up to 2A of load current. The TD1432 uses current-mode control to regulate the output voltage. The output voltage is measured at FB through a resistive voltage divider and amplified through the internal trans-conductance error amplifier. The output voltage of the error amplifier is compared to the switch current (measured internally) to control the output voltage. Setting the Output Voltage The output voltage is set using a resistive voltage divider connected from the output voltage to FB. The voltage divider divides the output voltage down to the feedback voltage by the ratio: R1 VFB = VOUT × ( ) R1 + R 2 Thus the output voltage is: VOUT = 1.23 × ( where ILOAD is the load current. The choice of which style inductor to use mainly depends on the price vs. size requirements and any EMI constraints. Input Capacitor The input current to the step-down converter is discontinuous, therefore a capacitor is required to supply the AC current while maintaining the DC input voltage. Use low ESR capacitors for the best performance. Ceramic capacitors are preferred, but tantalum or low-ESR electrolytic capacitors will also suffice. Choose X5R or X7R dielectrics when using ceramic capacitors. Since the input capacitor (C1) absorbs the input switching current, it requires and adequate ripple current rating. The RMS current in the input capacitor can be estimated by: R1 + R 2 ) R1 VOUT VOUT IC1 = ILOAD × √ × (1 − ) VIN VIN Inductor The inductor is required to supply constant current to the load while being driven by the switched input voltage. A larger value inductor will result in less ripple current that will in turn result in lower output ripple voltage. However, the larger value inductor will have a larger physical size, higher series resistance, and/or lower saturation current. A good rule for determining inductance is to allow the peak-to-peak ripple current to be approximately 30% or the maximum switch current limit. Also, make sure that the peak inductor current is below the maximum switch current limit. The inductance value can be calculated by: VOUT VOUT L= × (1 − ) fS × ∆IL VIN Where VOUT is the output voltage, VIN is the input voltage, fs is the switching frequency, and ∆IL is the peak-to-peak inductor ripple current. Choose an inductor that will not saturate under the April 1, 2022. maximum inductor peak current, calculated by: VOUT VOUT LP = ILOAD + × (1 − ) 2 × fS × L VIN The worst-case condition occurs at VIN=2VOUT, where IC1 = ILOAD/2. For simplification, use an input capacitor with a RMS current rating greater than half of the maximum load current. The input capacitor can be electrolytic, tantalum or ceramic. When using electrolytic or tantalum capacitor, be placed as close to the IC as possible. When using ceramic capacitors, make sure that they have enough capacitance to provide sufficient charge to prevent excessive voltage ripple at input. The input voltage ripple for low ESR capacitors can be estimated by: ILOAD VOUT VOUT ∆VIN = × (1 − ) C1 × fs VIN VIN where C1 is the input capacitance Value. Output Capacitor The output capacitor (C2) is required to maintain the DC output voltage. Ceramic, tantalum, or low ESR electrolytic capacitors are recommended. Under typical application Techcode Semiconductor Limited 6 www.techcodesemi.com Techcode® DATASHEET 2A 150KHz PWM Buck DC/DC Converter TD1432 conditions, a minimum ceramic capacitor value of 20µF is recommended on the output. Low ESR capacitors are preferred to keep the output voltage ripple low. The output voltage ripple can be estimated by: ∆VOUT = Vout Vout 1 ) × (R ESR + ) × (1fs ×L Vin 8×fS ×C2 Where C2 is the output capacitance value and RESR is the equivalent series resistance (ESR) value of the output capacitor. When using ceramic capacitors, the impedance at the switching frequency is dominated by the capacitance which is the main cause for the output voltage ripple. For simplification, the output voltage ripple can be estimated by: VOUT VOUT ∆VOUT = × (1 − ) 2 8 × fs × L × C2 VIN When using tantalum or electrolytic capacitors. The ESR dominates the impedance at the switching frequency. For simplification, the output ripple can be approximated to: VOUT VOUT ∆VOUT = × (1 − ) × R ESR fs × L VIN The characteristics of the output capacitor also affect the stability of the regulation system. The TD1432 can be optimized for a wide range of capacitance and ESR values. PCB Layout Guide 1. Input MLCC capacitor should be connected to the VIN pin and the GND pin as close as possible. 2. Keep sensitive signal traces such as trace connecting FB pin away from the VOUT pins 3. Make the current trace from SW pin to inductor to the GND as short as possible. 4. Pour a maximized copper area to the GNDs pin and the VIN pin to help thermal dissipation 。 April 1, 2022. Techcode Semiconductor Limited 7 www.techcodesemi.com Techcode® DATASHEET 2A 150KHz PWM Buck DC/DC Converter TD1432 Package Information SOP-8 Package Outline Dimensions April 1, 2022. Techcode Semiconductor Limited 8 www.techcodesemi.com Techcode® DATASHEET 2A 150KHz PWM Buck DC/DC Converter TD1432 Design Notes April 1, 2022. Techcode Semiconductor Limited 9 www.techcodesemi.com