TS2581CS RLG

TS2581 PWM Controller SOP-8 Pin Definition: 1. EN/CT 8. FB 2. GND 7. OVP 3. VGATE 6. VSENSE 4. VCC 5. GATE General Description The TS2581 integrates Pulse-Width-Modulation (PWM) control circuit into a single chip, mainly designs for powersupply regulator. All the functions include an error amplifier, a soft-start, UVLO, OVP, SCP, TSD circuitry. This device features an internal 100KHz oscillator, the UVLO makes sure that the outputs are off until the internal circuit operates normally. Features Ordering Information ● Input voltage：8V to 40V ● Duty ratio：0% to 100% PWM control ● Oscillation frequency：100K/300KHz ● Thermal Shutdown function. ● Short Circuit Protect (SCP). Application ● External SW P-channel MOS. ● Simple High-efficiency Step down Regulator ● External OVP setting function. ● ● Current mode non-synchronous PWM converter Charger ● ● External current limit setting. Telecommunication ● Under voltage Lockout. Part No. Package Packing TS2581CS RLG SOP-8 2.5kpcs / 13” Reel Note: “G” denotes for Halogen Free Absolute Maximum Rating Parameter VIN Pin Voltage Symbol Limit Unit VIN GND - 0.3 to GND + 45 V GND - 0.3 to VIN V VGATE,ISENSE Pin Voltage Feedback, OVP, EN/CT Pin Voltage GND - 0.3 to 6 V Switch Pin Voltage VSW GND - 0.3 to VIN + 0.3 V Power Dissipation PD (TJ – TA)/ θJA W Storage Temperature Range TST -40 to +165 °C Operating Temperature Range TOP -20 to +125 °C Operating Supply Voltage VOP +8.5 to +40 V Symbol Maximum 15 Thermal Information Parameter ӨJC Thermal Resistance (Junction to Case) Unit o C/W o Thermal Resistance (Junction to Ambient) ӨJA 40 C/W Note1: ӨJA is measured on the PCB with minimum copper area. 2 Note2: ӨJA is measured with the PCB copper area (need connect to GROUND pins) of approximately 0.5 in 1/7 Version: A11 TS2581 PWM Controller Electrical Specifications (Ta = 25oC unless otherwise noted, VIN=12V) Characteristics Symbol Conditions Feedback Voltage VFB IOUT=10mA Under Voltage Lockout UVLO Falling UVLO Hysteresis - OVP detect voltage VOVP Internal define Min. Typ. Max. Units 0.98 1 1.02 V - 6 - V - 0.8 - V 1.07 1.1 1.13 V Line Regulation REGLINE VIN=10 ~ 40V, IOUT=10mA - 0.5 1 % Load Regulation REGLOAD IOUT=0~3A, RSENSE = 33mΩ - 30 50 mV Quiescent Current ICCQ VFB = 1.5V, force driver off. - 3 6 mA Oscillator frequency FOSC IOUT = 0.5A 70 100 130 KHz Force driver on VFB = 0.6V - 100 - % Force driver off VFB = 1.5V - 0 - % - 110 - mV - - 0.4 V 0.5 - 1.5 V Max. Duty Cycle (ON) DC Min. Duty Cycle (OFF) Sense Voltage VCC-VSENSE EN/CT pin logic input threshold voltage VEN1 Shutdown mode VCT Auto restart, VFB1.10V, the OVP is happened that it can turn-off the driver. Under Voltage Lockout (UVLO) To avoid error-operation of the device at low input voltages an under voltage lockout is included that disables the device, if the input voltage falls below 6.0V Thermal Consderation The SOP-8L package needs a heat sink under most conditions. The heat sink connect exposed pad of TS2581 to obtain best effect. The size of the heat sink depends on the input voltage, output voltage, output current and ambient temperature. Typical Application Circuit VCC 10~36V ICL = RSENSE1 470uF 0.1u 1uF 8 7 6 5 L1 D1 4 3 2 1 VCC VGATE GATE VSENSE GND EN/CT OVP FB 5 R1 0R 66uH / 33uH R2 R3 C5 C4 Option 470uF R4 4 C3 D 3 2 1 S C2 P-MOS 33mR U2 C1 5V/3A U1 ( VCC - Vsense ) / Rsense 6 B340A 7 Option 8 C6 12K 12K R5 R6 3K 3K Option C7 0.1u AX3304/A TS2581 3/7 Version: A11 TS2581 PWM Controller Application Information Setting the Output Voltage Application circuit item shows the basic application circuit with adjustable output version. The external resistor sets the output voltage according to the following formula: VOUT = 1.0V × (1+ R3 ) R6 Table 1 Resistor select for output voltage setting VOUT R6 R3 5.0V 3.3V 3K 3K6 12K 8K2 Current Limit Protection The Current limit is set by outside resistance (RSENSE), When the SENSE pin voltage larger than 110mV, the current limit is happened that driver can be turned off until small than 90mV. The current limit set according to the following formula: Current Limit (A) = 110mV RSENSE The maximum output current table is shown as below; please refer the table to design. RSENSE (Ω) Current Limit (A) Maximum Output Current (A) 25m 30m 50m 75m 4.4 3.66 2.2 1.46 4.1 3.3 1.9 1.1 Inductor Selection For most designs, the different frequency can be reducing the inductor value; The TS2581 is suggested 22µH to 100µH for 100K to 300KHz frequencies. Please refer the below table to design. L1 recommend value (VIN=10~30V ,VOUT=5V, IOUT=2A) L1 Value (H) 68~100uF Where is inductor Ripple Current. Large value inductors lower ripple current and small value inductors result in high ripple currents. Choose inductor ripple current approximately 20% of the maximum load current 3A, ∆IL=0.6A. The DC current rating of the inductor should be at least equal to the maximum load current plus half the ripple current to prevent core saturation (3A+0.3A). Input Capacitor Selection This capacitor should be located close to the IC using short leads and the voltage rating should be approximately 1.5 times the maximum input voltage. The RMS current rating requirement for the input capacitor of a buck regulator is approximately 1⁄2 the DC load current. A low ESR input capacitor sized for maximum RMS current must be used. A 220~470µF low ESR capacitor for most applications is sufficient. 4/7 Version: A11 TS2581 PWM Controller Application Information (Continue) Output Capacitor Selection The output capacitor is required to filter the output and provide regulator loop stability. The important capacitor parameters are; the 100 KHz Equivalent Series Resistance (ESR), the RMS ripples current rating, voltage rating, and capacitance value. For the output capacitor, the ESR value is the most important parameter. The ESR can be calculated from the following formula. V RIPPLE = ∆ I L × ESR = 0.6A x 80mΩ= 48mV An aluminum electrolytic capacitor’s ESR value is related to the capacitance and its voltage rating. In most case, higher voltage electrolytic capacitors have lower ESR values. Most of the time, capacitors with much higher voltage ratings may be needed to provide the low ESR values required for low output ripple voltage. System stability is depending on output capacitor’s ESR, Correct to choose output capacitor’s ESR is very important. It is recommended to using a 220~470µF, the ESR values range is 40~130mΩ. EN/CT The pin is enable/shutdown and auto restart control functions. When system is normal operating, this pin is enable/shutdown function. Pulling this pin below a threshold voltage of under 0.3V shuts the regulator off, and pulling this pin from 0.5V to 1.5V turns the regulator on. However when VOUT is short (VFB