1999 June 10

26

Philips Semiconductors

Preliminary specification

5 V spindle & VCM driver combo

TDA5345HT

220

µV/G on the 1 st stage output.

pass filter pole. The internal RC low pass filter pole is 8 kHz typical. The window of the comparator input (ShockCompInP)

is programmable through the serial interface. The values are given in the following table:

Table 16 Window comparator threshold versus ShockThresh[1:0] (bits [9,8] in register #4):

Temperature monitor:

The TDA5345HT includes an analog circuitry that monitors the junction temperature.

Figure 25 shows its diagram:

SHOCKTHRESH[1:0]

WINDOW

2ND STAGE INPUT

SENSITIVITY

000

74 mV

227

µV

001

148 mV

454

µV

010

222 mV

681

µV

011

296 mV

908

µV

100

370 mV

1.135 mV

101

444 mV

1.362 mV

110

518 mV

1.589 mV

111

592 mV

1.816 mV

Fig.18 Shock sensor control circuitry

ShockCompOut

ShockFiltOut

ShockInput

ShockCom

Window

comparator

programmable

threshold

Shock Sensor

(ext.)

R

C

ShockRef

+

-

380k

Ω

20k

Ω

Amplifier x20

+

-

Cgain

2V

ShockAmpOut

+

-

Amplifier x16.3

1

2

3

4

(50)

(55)

(54)

(51)

(53)

(52)