Electronic Components Datasheet Search |
|
PTH08T230W Datasheet(PDF) 22 Page - Texas Instruments |
|
PTH08T230W Datasheet(HTML) 22 Page - Texas Instruments |
22 / 36 page www.ti.com UNDERVOLTAGE LOCKOUT (UVLO) Threshold Adjust R UVLO = 70.74-V THD V -4.26 THD k W (5) Calculated Values Inhibit/ UVLO Prog GND PTH08T230W 3 2 10 + GND RUVLO VI VI CI PTH08T230W, PTH08T231W SLTS265F – NOVEMBER 2005 – REVISED MAY 2007 The PTH08T230/231W power modules incorporate an input undervoltage lockout (UVLO). The UVLO feature prevents the operation of the module until there is sufficient input voltage to produce a valid output voltage. This enables the module to provide a clean, monotonic powerup for the load circuit, and also limits the magnitude of current drawn from the regulator’s input source during the power-up sequence. The UVLO characteristic is defined by the ON threshold (VTHD) voltage. Below the ON threshold, the Inhibit control is overridden, and the module does not produce an output. The hysteresis voltage, which is the difference between the ON and OFF threshold voltages, is set at 500 mV. The hysteresis prevents start-up oscillations, which can occur if the input voltage droops slightly when the module begins drawing current from the input source. The UVLO feature of the PTH08T230/231W module allows for limited adjustment of the ON threshold voltage. The adjustment is made via the Inhibit/UVLO control pin (pin 10) using a single resistor (see Figure 19). When pin 10 is left open circuit, the ON threshold voltage is internally set to its default value, which is 4.3 V. The ON threshold might need to be raised if the module is powered from a tightly regulated 12-V bus. Adjusting the threshold prevents the module from operating if the input bus fails to completely rise to its specified regulation voltage. Equation 5 determines the value of RUVLO required to adjust VTHD to a new value. The default value is 4.3 V, and it may be adjusted, but only to a higher value. Table 7 shows a chart of standard resistor values for RUVLO for different values of the ON threshold (VTHD) voltage. Table 7. Standard RUVLO values for Various VTHD values VTHD (V) 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0 RUVLO (kΩ) 88.7 52.3 37.4 28.7 23.2 19.6 16.9 14.7 13.0 11.8 10.5 9.76 8.87 Figure 19. UVLO Implementation 22 Submit Documentation Feedback Copyright © 2005–2007, Texas Instruments Incorporated Product Folder Link(s): PTH08T230W PTH08T231W |
Similar Part No. - PTH08T230W_07 |
|
Similar Description - PTH08T230W_07 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |