10
Rev. 0
OUTPUT CIRCUIT DESCRIPTION
Figure 12. Output Configuration Schematic
Selecting Channels
The LTC6563’s multiplexing capability allows compact
multichannel designs without external multiplexers,
using the CHSEL1 (MSB) and CHSEL0 (LSB) device pins
to select 1:4 channels. To select the active channel, the
jumpers shown in Figure 13 can be used. With the jumper
in the 1 position (side farthest from P9, silkscreen A), the
channel select pin will be tied to V
CCI
. In the 0 position
(side closest to P8, silkscreen B), the channel select pin
is grounded. Refer to Table 2 below for channel selection.
Alternatively, channel selection may be provided by SDP-
K1 (if present) with the manual channel selection jump-
ers lifted out and instead moved to the 2 pin headers
just above, as shown schematically in Figure 13 (from
DC2026C which refers to the SDP-K1 board).
Table 2. Channel Selection
CHSEL1
CHSEL0
ACTIVE CHANNEL
0
0
1
0
1
2
1
0
3
1
1
4
To evaluate the LTC6563 channel-to-channel switching
times, the center pin of the channel selection 3-pin jump-
ers can be tied to a high-speed pattern/pulse generator
(with the plastic shorting block(s)/jumpers not used).
These connections may need additional 50Ω termination
resistors for best signal integrity.
