TDA5345HT Datasheet, PDF (17/44 Pages) NXP Semiconductors – 5 V spindle & VCM driver combo

Philips Semiconductors
5 V spindle & VCM driver combo
Preliminary specification
TDA5345HT
Table 5 Numeral application with CLOCK = 16 MHz
DELAYS
Blank
WatchDog
StartUp
CLOCKOUTPRESCALER= CLOCKOUTPRESCALER= CLOCKOUTPRESCALER= CLOCKOUTPRESCALER=
CLOCK/4 = 4 MHZ
CLOCK/8 = 2 MHZ
CLOCK/16 = 1 MHZ
CLOCK/32 = 0.5 MHZ
MIN STEP MAX MIN STEP MAX MIN STEP MAX MIN STEP MAX
3 µs 4 µs 63 µs 7 µs
127 µs 128µs 2.05 ms 255 µs
4.1 ms 65.5 ms 65.5 ms 8.2 ms
8 µs
256 µs
8.2 ms
127 µs 15 µs 16 µs 255 µs 31 µs 32 µs 511 µs
4.0 ms 511 µs 512 µs 8.2 ms 1023 µs 1024 µs 16.4 ms
131 ms 16.4 ms 16.4 ms 262 ms 32.8 ms 32.8 ms 524 ms
TIMER 2
TIMER2 is used to measure the delay between two zero-crossings and also to set the maximum commutation delay
through comdelim delay:
11 10 9 8 7 6 5 4 3 2 1 0
ComDeLim
Fig.10 Timer 2 configuration.
Explanation: COMDELIM is the maximum value that can be reached by TIMER 2. So, this is the maximum delay
between 2 zero-crossings. The maximum commutation delay is then half this value!
Calculations:
Delay between 2 zero-crossings (∆ Zc):
step size = 2^LSB / ClockOutPrescaler
min
= (2^LSB-1) / ClockOutPrescaler (bits from 0 to (LSB-1) are internally set to 1)
maximum = (2^(MSB+1) - 1) / ClockOutPrescaler
Maximum commutation delay:
step size = 2^(LSB-1) / ClockOutPrescaler
maximum = (2^(MSB) - 1) / ClockOutPrescaler
Table 6 Numeral application with CLOCK = 16 MHz
DELAYS
∆ Z_C
ComDeLim
CLOCKOUTPRESCALER= CLOCKOUTPRESCALER= CLOCKOUTPRESCALER= CLOCKOUTPRESCALER=
CLOCK/4 = 4 MHZ
CLOCK/8 = 2 MHZ
CLOCK/16 = 1 MHZ
CLOCK/32 = 0.5 MHZ
MIN
63 µs
31 µs
STEP MAX MIN STEP MAX MIN STEP MAX MIN STEP MAX
64 µs 1.02 ms 127 µs 128 µs 2.05 µs 255 µs 256 µs 4.1 ms 511 µs 512 µs 8.2 ms
32 µs 511 ms 63 µs 64 µs 1.02 ms 127 µs 128 µs 2.05 ms 255 µs 256 µs 4.1 ms
1999 June 10
17