Electronic Components Datasheet Search |
|
TC170CPE Datasheet(PDF) 6 Page - TelCom Semiconductor, Inc |
|
TC170CPE Datasheet(HTML) 6 Page - TelCom Semiconductor, Inc |
6 / 8 page 4-124 TELCOM SEMICONDUCTOR, INC. CMOS CURRENT MODE PWM CONTROLLER TC170 4 3 3.15 CURRENT– SENSE AMPLIFIER TC170 VS N 1 I S VS = IS • RS N × + – + – Figure 5. External Clock Synchronization Figure 4. Master/Slave Parallel Operation Figure 3 Transformer Isolated Current Sense Undervoltage Lockout The undervoltage lockout circuit forces the TC170 out- puts OFF (low) if the supply voltage is below 7.7V. Threshold hysteresis is 0.75V and guarantees clean, jitter-free turn-on and turn-off points. The hysteresis also reduces capacitive filtering requirements at the PWM controller supply input (pin 15). Circuit Synchronization Current-mode-controlled power supplies can be oper- ated in parallel with a common load. Paralleled converters will equally share the load current. Voltage-mode control- lers unequally share the load current, decreasing system reliability. Two or more TC170 controllers can be slaved to- gether for parallel operation. Circuits can operate from a master TC170 internal oscillator with an external driver (Figure 4). Devices can also be slaved to an external oscillator (Figure 5). Disable internal slave device oscilla- tors by grounding pin 8. Slave controllers derive an oscilla- tor from the bidirectional synchronization output signal at pin 10. Pin 10 is bidirectional in that it is intended to be both a sync output and input. This is accomplished by making the output driver "weak." This is advantageous in that it elimi- nates an additional pin from the package but does not enable the device to directly drive another device. In order to make it an effective driver, a buffer is required (Figure 4). In order to use pin 10 as a sync input, it is necessary to overcome the internal driver. This requires a pulse with an amplitude equal to VIN. Since VIN must be above 8.25V for the undervoltage lockout to be disabled, a CMOS or open- collector TTL driver should be used. MASTER RO SYNC CMPTR SLAVE 9 8 9 8 210 7 7 1/2 TC4427 VDD TC170 10 CO VREF CO RO CMPTR SYNC TC170 1/2 TC4427 TC170 TC170 SYNC SYNC EXTERNAL* OSCILLATOR CO 29 29 10 15 15 8 10 VS + VDD *PULSE WIDTH OF OSCILLATOR IS = TD CO VREF RO RO VREF VIN VIN |
Similar Part No. - TC170CPE |
|
Similar Description - TC170CPE |
|
|
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 |