Announcements

From sunburn to sun earn – we’ve got the power! Watch our #poweringgreen videos now.

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
JC_huang
Level 1
Level 1
First like received First question asked Welcome!

I am confused about TDA38812 & TDA38813.

What’s the different between TDA38812 & TDA38813?

 

Thanks.

1 Solution
Vishnu_Pulik
Moderator
Moderator
Moderator
25 sign-ins 5 likes given First solution authored

Hi @JC_huang ,

The difference between TDA38812 and TDA38813 is listed in the below table.

Parameter TDA38812 TDA38813
Internal reference voltage  0.6V 0.9V
Output voltage range 0.6-5.5V 0.9-6V
Minimum Soft start time 1ms 1.5ms
OCP

OCP hiccup is active 3ms after the device is enabled. Once OCP hiccup is active, if the device detects over current condition for consecutive 40 cycles, or if the FB drops below under voltage protection  threshold, it enters hiccup mode and PGood flags low. In hiccup mode, the device latches off the Control MOSFET immediately, and latches off the Synchronous MOSFET after ZCD is detected. Meanwhile, the SS/VREF capacitor is also discharged. After about 11ms, the device will try to soft stat automatically. If the over current
condition still holds after 3ms of running, the device repeats this operation cycle until the over current condition disappears.

 

Vishnu_Pulik_3-1704713792978.png

 

OCP latch response is active 3ms after the device is enabled. Once it is active, if the device detects over current condition for consecutive 40 cycles, or if the FB drops below under voltage protection  threshold, the device latches off the Control MOSFET immediately and PGood flags low. The Synchronous MOSFET is turned off after ZCD is detected. The device will restart into a soft start when VIN, EN or VCC is cycled.

Vishnu_Pulik_4-1704713851858.png

 

 

 

 

 

 

 

UVP  Under Voltage Protection  provides additional protection during OCP fault or other faults. UVP protection is enabled when the soft-start reference rises above 160 mV. UVP circuitry monitors FB voltage. When FB is below the UVP threshold for 5 µs (typical), an undervoltage trip signal is triggered. PGood is pulled low after a delay of ~2 µs. The part continues to switch for ~5 µs after PGood is pulled low. Then the Control MOSFET is turned OFF and the Synchronous MOSFET is turned OFF after ZCD  is detected. Also, the SS/VREF capacitor is discharged. Then the TDA38812 enters hiccup mode with a blanking time of 11ms, during which the Control MOSFET and the Synchronous MOSFET remain off. After the completion of blanking time, the TDA38812 attempts to recover to the nominal output voltage with a soft start. The TDA38812 will repeat
hiccup mode and attempt to recover until the UVP condition is removed.

 Under Voltage Protection provides additional protection during OCP fault or other faults. UVP protection is enabled when the soft-start reference rises above 160 mV. UVP circuitry monitors FB voltage. When FB is below the UVP threshold for 5 µs (typical), an undervoltage trip signal is triggered. PGood is pulled low after a delay of ~2µs. The part continues to switch for ~5µs after PGood is pulled low. Then, the Control MOSFET is latched OFF and the Synchronous MOSFET is turned off after ZCD is detected. Also, the SS/VREF capacitor is discharged. The device will restart into a soft start when VIN, EN or VCC is cycled.

 

 

 

 

 

 

Regards,

Vishnu P

 

 

View solution in original post

2 Replies
Carl_Ho
Level 1
Level 1
First like received First reply posted 10 sign-ins

Dear JC,

Pls see the different as below information, many thanks.

TDA38812/Vfb 0.6V/SS min 1mS/Non latch OCP

TDA38813/Vfb 0.9V/SS min 1.5mS/latch OCP

#TDA38812

#TDA38813

Vishnu_Pulik
Moderator
Moderator
Moderator
25 sign-ins 5 likes given First solution authored

Hi @JC_huang ,

The difference between TDA38812 and TDA38813 is listed in the below table.

Parameter TDA38812 TDA38813
Internal reference voltage  0.6V 0.9V
Output voltage range 0.6-5.5V 0.9-6V
Minimum Soft start time 1ms 1.5ms
OCP

OCP hiccup is active 3ms after the device is enabled. Once OCP hiccup is active, if the device detects over current condition for consecutive 40 cycles, or if the FB drops below under voltage protection  threshold, it enters hiccup mode and PGood flags low. In hiccup mode, the device latches off the Control MOSFET immediately, and latches off the Synchronous MOSFET after ZCD is detected. Meanwhile, the SS/VREF capacitor is also discharged. After about 11ms, the device will try to soft stat automatically. If the over current
condition still holds after 3ms of running, the device repeats this operation cycle until the over current condition disappears.

 

Vishnu_Pulik_3-1704713792978.png

 

OCP latch response is active 3ms after the device is enabled. Once it is active, if the device detects over current condition for consecutive 40 cycles, or if the FB drops below under voltage protection  threshold, the device latches off the Control MOSFET immediately and PGood flags low. The Synchronous MOSFET is turned off after ZCD is detected. The device will restart into a soft start when VIN, EN or VCC is cycled.

Vishnu_Pulik_4-1704713851858.png

 

 

 

 

 

 

 

UVP  Under Voltage Protection  provides additional protection during OCP fault or other faults. UVP protection is enabled when the soft-start reference rises above 160 mV. UVP circuitry monitors FB voltage. When FB is below the UVP threshold for 5 µs (typical), an undervoltage trip signal is triggered. PGood is pulled low after a delay of ~2 µs. The part continues to switch for ~5 µs after PGood is pulled low. Then the Control MOSFET is turned OFF and the Synchronous MOSFET is turned OFF after ZCD  is detected. Also, the SS/VREF capacitor is discharged. Then the TDA38812 enters hiccup mode with a blanking time of 11ms, during which the Control MOSFET and the Synchronous MOSFET remain off. After the completion of blanking time, the TDA38812 attempts to recover to the nominal output voltage with a soft start. The TDA38812 will repeat
hiccup mode and attempt to recover until the UVP condition is removed.

 Under Voltage Protection provides additional protection during OCP fault or other faults. UVP protection is enabled when the soft-start reference rises above 160 mV. UVP circuitry monitors FB voltage. When FB is below the UVP threshold for 5 µs (typical), an undervoltage trip signal is triggered. PGood is pulled low after a delay of ~2µs. The part continues to switch for ~5µs after PGood is pulled low. Then, the Control MOSFET is latched OFF and the Synchronous MOSFET is turned off after ZCD is detected. Also, the SS/VREF capacitor is discharged. The device will restart into a soft start when VIN, EN or VCC is cycled.

 

 

 

 

 

 

Regards,

Vishnu P