CHAPTER 3 HARDWARE SETTINGS AND FUNCTIONS
User’s Manual U17029EJ3V0UM
23
(3) When using resistors (auto switch)
Figure 3-4. When Using Resistors
RESET
Reset circuit
Note
RESET_OUT
RESET_IN
1 k
Ω
Target device
Note
Be sure to insert a buffer when connecting via resistors. In particular, if a power-on reset circuit is
connected directly, the time constant may become invalid due to RESET_OUT output from the QB-
78K0MINI, in which case a lack of drive capacity in the circuit where the reset occurs may prevent
proper detection of the reset. A reset circuit example is shown below.
Buffer
Correct circuit example
To RESET_IN
Reset circuit
V
DD
V
DD
Reset circuit
Incorrect circuit example
To RESET_IN
Caution The reset is driven from the QB-78K0MINI when a resistor is connected between RESET_IN
and RESET_OUT and the QB-78K0MINI is connected. When the QB-78K0MINI is not
connected, the reset is driven via the resistor and from within the target device.
Remark
All constants shown in this circuit are reference values.
