iC-MQ
PROGRAMMABLE 9-BIT
Sin/Cos INTERPOLATION IC WITH RS422 DRIVER
Rev D4, Page 29/39
Output Driver Configuration
The output drivers can be used as push-pull, lowside
or highside drivers; the mode of operation is deter-
mined by TRIHL(1:0).
In order to avoid steep edges when transmitting via
short wires the slew rate can be set using SSR to suit
the length of the cable. This can result in a limiting
of the maximum permissible output frequency if at the
same time the RS422 specification is to be adhered
to (for example, to 300 kHz at a slew rate of 300 ns;
the tolerances in Electrical Characteristics, numbers
506/507, must be observed).
The driver output short-circuit current can be set by
SIK and can be minimized when connecting to logic or
to an external 24 V line driver. If the outputs are used
as RS422-compatible 5 V drivers, it is recommended
that SIK = 11 to keep the power dissipation of iC-MQ
low.
TRIHL
Code
00
01
10
11
Adr 0x1E, bit 1:0
Function
Push-pull operation
Highside driver mode (P channel open drain)
Lowside driver mode (N channel open drain)
Not permitted
SIK
Code
00
01
10
11
Note
Adr 0x1E, bit 5:4
Function
typ.
typ.
typ.
typ.
2 mA, linking logic or driver ICs
8 mA
40 mA
100 mA, recommended for RS422
See Elec. Char. Nos. 503/504
Table 51: Output Short-Circuit Current
Minimum Phase Distance
The minimum phase distance for A/B/Z and
CPD/CPU/CP output signals can be preselected using
MTD(3:0). This setting limits the maximum possible
output frequency for safe transmission to counters
which cannot debounce spikes or only permit a low
input frequency.
When preselecting the minimum edge distance the
configuration of the RS422 output drivers (with regard
to the driver current and slew rate) and the length of
cable used must be taken into account.
MTD
Code
0x0
0x1
0x2
0x3
0x4
0x5
0x6
0x7
0x8
0x9
0xA
0xB
0xC
0xD
0xE
0xF
Note
Adr 0x1D, bit 7:4
Mode ABZ
: t
MTD
220 ns
410 ns
600 ns
800 ns
1.0 µs
1.2 µs
1.4 µs
1.6 µs
220 ns
410 ns
600 ns
800 ns
1.0 µs
1.2 µs
1.4 µs
1.6 µs
Mode 191/193: tclk()lo
110 ns
205 ns
300 ns
400 ns
500 ns
600 ns
700 ns
800 ns
50 ns
50 ns
50 ns
50 ns
50 ns
50 ns
50 ns
50 ns
Table 49: Output Drive Mode
SSR
Code
00
01
10
11
Note
Adr 0x1E, bit 3:2
Function
Nominal value 12 ns
Nominal value 25 ns
Nominal value 80 ns
Nominal value 220 ns
See Elec. Char. Nos. 506/507
Table 50: Output Slew Rate
All timing specifications are nominal values, see
Elec. Char. No. 515 for tolerances.
Table 52: Minimum Phase Distance
ICHAUS [ IC-HAUS GMBH ]
