Electronic Components Datasheet Search |
|
UCC38502DW Datasheet(PDF) 7 Page - Texas Instruments |
|
|
UCC38502DW Datasheet(HTML) 7 Page - Texas Instruments |
7 / 35 page UCC28500, UCC28501, UCC28502, UCC28503 UCC38500, UCC38501, UCC38502, UCC38503 SLUS419C − AUGUST 1999 − REVISED NOVEMBER 2001 7 www.ti.com pin assignments (continued) SS2: (soft-start for PWM) SS2 is at ground for either enable low or OVP/ENBL below the UVLO2 threshold conditions. When enabled, SS2 charges an external capacitor with a current source. This voltage is used as the voltage error signal during start-up, enabling the PWM duty cycle to increase slowly. In the event of a disable command or a UVLO2 dropout, SS2 quickly discharges to disable the PWM. VAOUT: (voltage amplifier output) This is the output of the operational amplifier that regulates output voltage. The voltage amplifier output is internally limited to approximately 5.5 V to prevent overshoot. VCC: (positive supply voltage) Connect to a stable source of at least 20 mA between 12 V and 17 V for normal operation. Bypass VCC directly to GND to absorb supply current spikes required to charge external MOSFET gate capacitances. To prevent inadequate gate drive signals, the output devices are inhibited unless VCC exceeds the upper under-voltage lockout threshold and remains above the lower threshold. VERR: (voltage amp error signal for the second stage) The error signal is generated by an external amplifier which drives this pin. This pin has an internal 4.5-V voltage clamp that limits GT2 to less than 50% duty cycle to ensure transformer reset in the typical application. VFF: (RMS feed forward signal) VFF signal is generated at this pin by mirroring one-half of IAC into a single pole external filter. At low line, the VFF voltage should be 1.4 V. VSENSE: (voltage amplifier inverting input) This is normally connected to a compensation network and to the boost converter output through a divider network. VREF: (voltage reference output) VREF is the output of an accurate 7.5-V voltage reference. This output is capable of delivering 10 mA to peripheral circuitry and is internally short-circuit current limited. VREF is disabled and remains at 0 V when VCC is below the UVLO threshold. Bypass VREF to GND with a 0.1- µF or larger ceramic capacitor for best stability. |
Similar Part No. - UCC38502DW |
|
Similar Description - UCC38502DW |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | 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 |