Skip to Content

Holtek's new generation Touch Key Flash series MCUs are fully integrated with touch key functions, communication interfaces and display functions thus reducing greatly the need for external components. With the features of high S/N ratio touch switch control, power fluctuation rejection and excellent noise immunity, the stability of these touch keys has been greatly improved, thus offering solutions over traditional mechanical keys with their inherent weakness of rapid wear and tear and manufacturing complexity. These features combine to ensure effective and rapid product development in areas such as household appliances and other touch key controlled products.

Functional Description Functional Description

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Question 8

Question 9

Question 10

Question 11

Question 12

Question 13

Question 14

Question 15

Question 16


Question 1

How the Cref pin used in the BS80xB devices?

Answer

The Cref pin in the BS80xB devices can be used in the following way to adjust the sensitivity of all the switches. (For actual implementation please see the BS80xB application note)
a. Connect a 0pF~10pF capacitor between the Cref pin and ground.
b. Connect a PADCref to the Cref pin.

« back


Question 2

What's the difference between the BS80xC and BS80xB series MCUs?

Answer

The following table indicates the differences with 1-key touch switch devices.

From the above table, the main differences lie in the Key Response Time and Power Consumption.

« back


Question 3

With the exception of the operating mode, key response time and power consumption, are there any other differences between the BS80xC and BS80xB?

Answer

There are no other differences as the design of the BS80xC series device is based on the BS80xB series.

« back


Question 4

What is the difference in the SCD functional specification between the BS80xC and BS80xB series MCUs?

Answer

As the two series have different operating modes, the SCD commands also differ. However, both the SCD transmission protocol and specifications are the same. (For detailed SCD commands refer to the BS80xC/BS80xB datasheet)

« back


Question 5

Are the BS80xC series package types compatible with the BS80xB series?

Answer

They are fully compatible.

« back


Question 6

Is there any other FAQ information for the BS80xC series MCUs?

Answer

As the BS80xC is based on the BS80xB, for any other related questions refer to the BS80xB FAQs.得解答。

« back


Question 7

What are the real differences between the BS80xC and BS80xB in terms of their different operating modes?

Answer

Note 1: In the single key wake-up mode, KEY0 must be pressed before the system enters the normal mode at which point all the keys will be effective.

« back


Question 8

What does the part number of the BS812A-1, BS813A-1, BS814A-1, BS814A-2, BS816A-1, BS818A-2, BS8112A-3 or BS8116A-3 represent?

Answer

a. BS812A-1 represents 2Key Touch Key, parallel output
b. BS813A-1 represents 3Key Touch Key, parallel output
c. BS814A-1 represents 4Key Touch Key, parallel output
d. BS814A-2 represents 4Key Touch Key, 2-wire serial output
e. BS816A-1 represents 6Key Touch Key, parallel output
f. BS818A-2 represents 8Key Touch Key, 2-wire serial output
g. BS8112A-3 represents 12Key Touch Key, I²C output
h. BS8116A-3 represents 16Key Touch Key, I²C output
Note: the "- 1" suffix indicates a parallel output mode, a "-2" suffix indicates a two-wire serial output mode and a "-3" indicates an I²C communication mode.

« back


Question 9

What is the power consumption of the BS812A-1, BS813A-1, BS814A-1, BS814A-2, BS816A-1, BS818A-2, BS8112A-3 and BS8116A-3? Are these devices suitable for use in battery powered products?

Answer

The BS81XA series devices will automatically enter the standby mode if no touch key actions are detected during 8 seconds. As the standby current is very low, which is shown in the following table, the devices are suitable for use in powers senstivite products.

Note: There are two power-saving modes which are option selected.

« back


Question 10

What specific advantages do the BS81XXX series devices possess?

Answer

  • No need for device coding resulting in easier application development.
  • Low standby current therefore suitable for use in battery powered products
  • High noise rejection allowing use in a wide range of AC power product applications
  • Excellent immunity against power supply variations eliminating the need for an additional external LDO
  • These peripheral touch devices can directly connect to a Holtek host MCU

« back


Question 11

How many touch keys are there in the BS81XXX series devices?

Answer

BS812A-1→2 touch keys
BS813A-1→3 touch keys
BS814A-1→4 touch keys
BS814A-2→4 touch keys
BS816A-1→6 touch keys
BS818A-2→8 touch keys
BS8112A-3→12 touch keys
BS8116A-3→16 touch keys

« back


Question 12

What package types are supplied for the BS81xxx series devices?

Answer

« back


Question 13

What are the basic functions of the BS81xxx series?

Answer

  • LSC (Lower Standby Current): general power-saving mode/higher power-saving mode  (longer wake-up time of about 0.5~1s)
  • OMS (Output Mode Select):
    NMOS / CMOS for BS816A-1
    Serial / Binary for BS818A-2
    One Shot / Level Hold with IRQ for BS8112A-3/BS8116A-3

« back


Question 14

What are the BS81 series application circuits?

Answer

Note:
1. Ct (C threshold) is an adjustment trigger threshold capacitor which has a range of 0~25pF.
2. Adjust Ct to change the sensitivity. Higher values of Ct result in lower sensitivity values.
3. The sensitivity of the BS8112A-3 or BS8116A-3 device can be setup using an I²C command.

« back


Question 15

What is the operating temperature of the BS81XXX series devices?

Answer

The BS81xx series of MCUs can execute normal operations at an industrial grade temperature range of -40°C~+85°C.

« back


Question 16

What is the I²C communication frequency of the BS81XXX series devices?

Answer

Normal ≦100KHz

« back