tb62217afg TOSHIBA Semiconductor CORPORATION, tb62217afg Datasheet - Page 23

• Manufacturer Part Number: tb62217afg
• Description: Pwm Drive Stepping Motor Driver / Brush Dc Motor Driver Selectable, Dc-dc Converter And Reset Function Ic
• Manufacturer: TOSHIBA Semiconductor CORPORATION

[OSC_M/OSC_D open-state detection circuit]
The OSC_M/OSC_D open-state detection circuit tries to detect when a capacitor comes off the OSC_M or
OSC_D for some reason by monitoring to see if the frequency gets out of the rated frequency range. When it
detects such an event, it shuts down the IC.
The open-state detection circuit is initially off when the power is turned on.
(To cause it to run, a serial signal must be supplied to make the corresponding bit high.)
The frequency range settings are stated below.
(1) Shut down if the current frequency does not fall in the range: OSC_M frequency/64 ! OSC_D frequency
(2) Shut down if the current frequency does not fall in the range: OSC_D frequency u 32 ! OSC_M
Example 1: If the OSC_M frequency is 800 kHz
! OSC_M frequency/2
frequency ! OSC_D frequency u 2
2: If the OSC_D frequency is 100 kHz
The IC is shut down when OSC_D frequency > 400 kHz or OSC_D frequency < 12.5 kHz.
The IC is shut down when OSC_M frequency > 3200 kHz or OSC_M frequency 200 kHz.
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TB62217AFG
2004-11-12