Rainbow Electronics MAX106 User Manual

Page 23

MAX106

±5V, 600Msps, 8-Bit ADC with On-Chip

2.2GHz Bandwidth Track/Hold Amplifier

______________________________________________________________________________________

asserted, the auxiliary port contained “even” samples
while the primary port contained “odd” samples. After
RSTOUT is deasserted (which marks the start of the
DREADY clock’s reset phase), note that the order of the
samples in the ports has been reversed. The auxiliary
port also contains an out-of-sequence sample. This is a
consequence of the “swallowed” clock cycle that was
needed to resynchronize DREADY to the reset phase.
Also note that the older sample data is always in the aux-
iliary port, regardless of the DREADY phase.

These examples show the combinations that result with
a reset input signal of two clock cycles. It is also possi-
ble to successfully reset the internal MAX106 demux
with a reset pulse only one clock cycle long, proving
the setup-time and hold-time requirements are met with
respect to the sample clock. However, this is not rec-
ommended when additional external demuxes are
used.

Note that many external demuxes require their reset
signals to be asserted while they are clocked, and may
require more than one clock cycle of reset. More impor-
tantly, if the phase of the DREADY clock is such that a
clock pulse will be “swallowed” to resynchronize, then

no reset output will occur at all. In effect, the RSTOUT
signal will be “swallowed” along with the clock pulse.
The best method to ensure complete system reset is to
assert RSTIN for the appropriate number of DREADY
clock cycles required to complete reset of the external
demuxes.

Die Temperature Measurement

For applications that require monitoring of the die tem-
perature, it is possible to determine the die temperature
of the MAX106 under normal operating conditions by
observing the currents I

CONST

and I

PTAT

, at contacts

ICONST and IPTAT. I

CONST

and I

PTAT

are two 100µA

(nominal) currents that are designed to be equal at
+27°C. These currents are derived from the MAX106’s
internal precision +2.5V bandgap reference. I

CONST

designed to be temperature independent, while I

PTAT

directly proportional to the absolute temperature. These
currents are derived from pnp current sources refer-
enced from V

I and driven into two series diodes con-

nected to GNDI. The contacts ICONST and IPTAT may
be left open because internal catch diodes prevent sat-
uration of the current sources. The simplest method of

NOTE: DREADY PHASE WAS ADJUSTED TO MATCH THE RESET PHASE BY “SWALLOWING” ONE INPUT CLOCK CYCLE.
THE AUXILIARY PORT CONTAINS AN OUT-OF-SEQUENCE SAMPLE AS A RESULT OF THE DELAY.

CLK-

CLK+

n+1

n+2

n+3

n+4

n+5

n+6

n+7

n+8

n+9

n+10

n+11

n+12

n+13

ADC SAMPLE NUMBER

ADC SAMPLES ON THE RISING EDGE OF CLK+

CLOCK PULSE “SWALLOWED”

OUT-OF-SEQUENCE SAMPLE

CLK

DREADY

DREADY+

DREADY-

RSTIN+

RSTIN-

RSTOUT+

RSTOUT-

RESET

INPUT

n-1

n+1

n-2

AUXILIARY

DATA PORT

PRIMARY

DATA PORT

n+2

n+4

RESET OUT

DATA PORT

Figure 19. Reset Output Timing in Demuxed DIV2 Mode (DREADY Realigned)