Low-Jitter Configurable HCSL Oscillator
DSC2040
Pin Description
Pin No.
Pin Name Pin Type
Description
Enables outputs when high and disables when low
Leave unconnected or grounded
Leave unconnected or grounded
Ground
Least significant bit for frequency selection
Most significant bit for frequency selection
Leave unconnected or grounded
Positive HCSL Output
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Enable
NC
NC
GND
FS0
I
NA
NA
Power
I
FS1
I
NC
NA
O
O
NA
NA
Power
Power
NA
Output+
Output-
NC
Negative HCSL Output
Leave unconnected or grounded
Leave unconnected or grounded
Power Supply
Power Supply
Leave unconnected or grounded
NC
VDD2
VDD
NC
Operational Description
The DSC2040 is a HCSL oscillator consisting of
a MEMS resonator and a support PLL IC. The
different frequencies. Two control pins (FS0 –
FS1) select the output frequency. Discera
supports customer defined versions of the
DSC2040. Standard frequency options are
described in the following sections.
HCSL
output
is
generated
through
independent 8-bit programmable dividers from
the output of the internal PLL.
The actual frequency output by the DSC2040
is controlled by an internal pre-programmed
When Enable (pin 1) is floated or connected to
VDD, the DSC2040 is in operational mode.
Driving Enable to ground will tri-state output
driver (hi-impedance mode).
memory (OTP).
This memory stores all
coefficients required by the PLL for up to four
Output Clock Frequencies
Table 1 lists the standard frequency configurations and the associated ordering information to be
used in conjunction with the ordering code. Customer defined combinations are available.
Table 1. Pre-programmed pin-selectable output frequency combinations
Freq Select Bits [FS1, FS0] – Default is [11]
Ordering
Info
Freq
(MHz)
00
01
10
11
D0001
D000X
fOUT
fOUT
125
156.25
200
100
Contact factory for additional configurations.
Frequency select bit are weakly tied high so if left unconnected the default setting will be [11] and
the device will output the associated frequency highlighted in Bold.
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DSC2040
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MICREL [ MICREL SEMICONDUCTOR ]
