MAXIM MAX104

19-1459; Rev 1; 5/99
KIT
ATION
EVALU
LE
B
A
IL
A
AV
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
The MAX104 PECL-compatible, 1Gsps, 8-bit analog-todigital converter (ADC) allows accurate digitizing of
analog signals with bandwidths to 2.2GHz. Fabricated
on Maxim’s proprietary advanced GST-2 bipolar
process, the MAX104 integrates a high-performance
track/hold (T/H) amplifier and a quantizer on a single
monolithic die.
The innovative design of the internal T/H, which has an
exceptionally wide 2.2GHz full-power input bandwidth,
results in high performance (greater than 7.5 effective
bits) at the Nyquist frequency. A fully differential comparator design and decoding circuitry reduce out-ofsequence code errors (thermometer bubbles or sparkle
codes) and provide excellent metastable performance
of one error per 1016 clock cycles. Unlike other ADCs
that can have errors resulting in false full- or zero-scale
outputs, the MAX104 limits the error magnitude to
1LSB.
The analog input is designed for either differential or
single-ended use with a ±250mV input voltage range.
Dual, differential, PECL-compatible output data paths
ensure easy interfacing and include an 8:16 demultiplexer feature that reduces output data rates to one-half
the sampling clock rate. The PECL outputs can be
operated from any supply between +3V to +5V for compatibility with +3.3V or +5V referenced systems. Control
inputs are provided for interleaving additional MAX104
devices to increase the effective system sampling rate.
The MAX104 is packaged in a 25mm x 25mm, 192-contact Enhanced Super-Ball Grid Array (ESBGA™) and is
specified over the commercial (0°C to +70°C) temperature range.
Features
♦ 1Gsps Conversion Rate
♦ 2.2GHz Full-Power Analog Input Bandwidth
♦ >7.5 Effective Bits at fIN = 500MHz (Nyquist
Frequency)
♦ ±0.25LSB INL and DNL
♦ 50Ω Differential Analog Inputs
♦ ±250mV Input Signal Range
♦ On-Chip, +2.5V Precision Bandgap Voltage
Reference
♦ Latched, Differential PECL Digital Outputs
♦ Low Error Rate: 10-16 Metastable States at 1Gsps
♦ Selectable 8:16 Demultiplexer
♦ Internal Demux Reset Input with Reset Output
♦ 192-Contact ESBGA Package
Ordering Information
PART
TEMP. RANGE
MAX104CHC
0°C to +70°C
PIN-PACKAGE
192 ESBGA
192-Contact ESBGA
Ball Assignment Matrix
TOP VIEW
Applications
Digital RF/IF Signal Processing
Direct RF Downconversion
High-Speed Data Acquisition
Digital Oscilloscopes
High-Energy Physics
Radar/Sonar/ECM Systems
ATE Systems
MAX104
Typical Operating Circuit appears at end of data sheet.
ESBGA is a trademark of Amkor/Anam.
ESBGA
________________________________________________________________ Maxim Integrated Products
For the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
1
MAX104
General Description
MAX104
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
ABSOLUTE MAXIMUM RATINGS
VCCA to GNDA .........................................................-0.3V to +6V
VCCD to GNDD.........................................................-0.3V to +6V
VCCI to GNDI ............................................................-0.3V to +6V
VCCO to GNDD ........................................-0.3V to (VCCD + 0.3V)
AUXEN1, AUXEN2 to GND .....................-0.3V to (VCCD + 0.3V)
VEE to GNDI..............................................................-6V to +0.3V
Between GNDs......................................................-0.3V to +0.3V
VCCA to VCCD .......................................................-0.3V to +0.3V
VCCA to VCCI.........................................................-0.3V to +0.3V
PECL Digital Output Current ...............................................50mA
REFIN to GNDR ........................................-0.3V to (VCCI + 0.3V)
REFOUT Current ................................................+100µA to -5mA
ICONST, IPTAT to GNDI .......................................-0.3V to +1.0V
TTL/CMOS Control Inputs (DEMUXEN,
DIVSELECT)..........................................-0.3V to (VCCD + 0.3V)
RSTIN+, RSTIN- ......................................-0.3V to (VCCO + 0.3V)
VOSADJ Adjust Input ................................-0.3V to (VCCI + 0.3V)
CLK+ to CLK- Voltage Difference..........................................±3V
CLK+, CLK-.....................................(VEE - 0.3V) to (GNDD + 1V)
CLKCOM.........................................(VEE - 0.3V) to (GNDD + 1V)
VIN+ to VIN- Voltage Difference ............................................±2V
VIN+, VIN- to GNDI................................................................±2V
Continuous Power Dissipation (TA = +70°C)
192-Contact ESBGA (derate 61mW/°C above +70°C) ......4.88W
(with heatsink and 200 LFM airflow,
derate 106mW/°C above +70°C) ........................................8.48W
Operating Temperature Range
MAX104CHC........................................................0°C to +70°C
Operating Junction Temperature.....................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
DC ELECTRICAL CHARACTERISTICS
(VCCA = VCCI = VCCD = +5.0V ±5%, VEE = -5.0V ±5%, VCCO = +3.0V to VCCD, REFIN connected to REFOUT, TA = TMIN to TMAX,
unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
0.5
LSB
ACCURACY
Resolution
RES
Integral Nonlinearity (Note 1)
INL
TA = +25°C
-0.5
±0.25
Differential Nonlinearity (Note 1)
DNL
TA = +25°C
-0.5
±0.25
Missing Codes
8
Bits
No missing codes guaranteed
0.5
LSB
None
Codes
525
mVp-p
51
Ω
ANALOG INPUTS
Full-Scale Input Range
VFSR
Note 1
Common-Mode Input Range
VCM
Signal + offset w.r.t. GNDI
Input Resistance
RIN
VIN+ and VIN- to GNDI, TA = +25°C
Input Resistance Temperature
Coefficient
TCR
475
500
±0.8
49
50
V
150
ppm/°C
VOS ADJUST CONTROL INPUT
Input Resistance (Note 2)
RVOS
Input VOS Adjust Range
VOSADJ = 0 to 2.5V
14
25
kΩ
±4
±5.5
LSB
2.475
2.50
REFERENCE INPUT AND OUTPUT
Reference Output Voltage
Reference Output Load
Regulation
Reference Input Resistance
2
REFOUT
Driving REFIN input only
∆REFOUT 0 < ISOURCE < 2.5mA
RREF
Referenced to GNDR
4
5
_______________________________________________________________________________________
2.525
V
5
mV
kΩ
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
(VCCA = VCCI = VCCD = +5.0V ±5%, VEE = -5.0V ±5%, VCCO = +3.0V to VCCD, REFIN connected to REFOUT, TA = TMIN to TMAX,
unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
48
50
52
Ω
CLOCK INPUTS (Note 3)
Clock Input Resistance
RCLK
Input Resistance Temperature
Coefficient
TCR
CLK+ and CLK- to CLKCOM, TA = +25°C
150
ppm/°C
TTL/CMOS CONTROL INPUTS (DEMUXEN, DIVSELECT)
High-Level Input Voltage
VIH
Low-Level Input Voltage
VIL
2.0
High-Level Input Current
IIH
VIH = 2.4V
Low-Level Input Current
IIL
VIL = 0
V
-1
0.8
V
50
µA
1
µA
DEMUX RESET INPUT (Note 4)
Digital Input High Voltage
VIH
Digital Input Low Voltage
VIL
-1.165
V
-1.475
V
PECL DIGITAL OUTPUTS (Note 5)
Digital Output High Voltage
VOH
-1.025
-0.880
V
Digital Output Low Voltage
VOL
-1.810
-1.620
V
480
780
mA
108
150
mA
POWER REQUIREMENTS
Positive Analog Supply Current
ICCA
Positive Input Supply Current
ICCI
Negative Input Supply Current
IEE
Digital Supply Current
-290
ICCD
-210
mA
205
340
mA
115
mA
Output Supply Current (Note 6)
ICCO
75
Power Dissipation (Note 6)
PDISS
5.25
W
Common-Mode Rejection Ratio
(Note 7)
CMRR
VIN+ = VIN- = ±0.1V
40
68
dB
Positive Power-Supply Rejection
Ratio (Note 8)
PSRR+
(Note 9)
40
73
dB
Negative Power-Supply
Rejection Ratio (Note 8)
PSRR-
(Note 10)
40
68
dB
_______________________________________________________________________________________
3
MAX104
DC ELECTRICAL CHARACTERISTICS (continued)
MAX104
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
AC ELECTRICAL CHARACTERISTICS
(VCCA = VCCI = VCCD = +5.0V, VEE = -5.0V, VCCO = +3.3V, REFIN connected to REFOUT, fS = 1Gsps, fIN at -1dBFS, TA = +25°C,
unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ANALOG INPUT
Analog Input Full-Power
Bandwidth
Analog Input VSWR
Transfer Curve Offset
BW-3dB
VSWR
VOS
2.2
fIN = 500MHz
GHz
1.1:1
VOSADJ control input open
-1.5
0
V/V
+1.5
LSB
DYNAMIC SPECIFICATIONS
ENOB1000
Effective Number of Bits
(Note 11)
Signal-to-Noise Ratio
(No Harmonics)
Total Harmonic Distortion
(Note 12)
Spurious-Free Dynamic Range
Signal-to-Noise Ratio and
Distortion (Note 11)
Two-Tone Intermodulation
4
fIN = 1000MHz
ENOB500
fIN = 500MHz
ENOB125
fIN = 125MHz
SNR1000
fIN = 1000MHz
SNR500
fIN = 500MHz
SNR125
fIN = 125MHz
THD1000
fIN = 1000MHz
THD500
fIN = 500MHz
THD125
fIN = 125MHz
SFDR1000
fIN = 1000MHz
SFDR500
fIN = 500MHz
SFDR125
fIN = 125MHz
SINAD1000
fIN = 1000MHz
SINAD500
fIN = 500MHz
SINAD125
fIN = 125MHz
IMD
Differential
7.52
Single-ended
Differential
7.40
7.2
Single-ended
Differential
7.55
7.49
7.4
7.74
Single-ended
7.73
Differential
46.4
Single-ended
Differential
46.4
43.5
Single-ended
Differential
47.0
47.1
44.2
47.4
Differential
-52.6
Single-ended
-49.6
-50
Single-ended
Differential
-52.5
-51.3
-61
-67.4
Differential
52.8
Single-ended
52.5
50
Single-ended
Differential
52.3
52.3
62
69.5
Differential
47.0
Single-ended
46.3
45.1
Single-ended
Differential
Single-ended
fIN1 = 124MHz, fIN2 = 126MHz,
at -7dB below full-scale
dB
68.9
Single-ended
Differential
dB
-66.2
Single-ended
Differential
dB
47.4
Single-ended
Differential
Bits
47.2
46.9
46.3
dB
48.3
48.3
-57.7
_______________________________________________________________________________________
dB
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
(VCCA = VCCI = VCCD = +5.0V, VEE = -5.0V, VCCO = +3.3V, REFIN connected to REFOUT, fS = 1Gsps, fIN at -1dBFS, TA = +25°C,
unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
TIMING CHARACTERISTICS
Maximum Sample Rate
fMAX
Clock Pulse Width Low
tPWL
Figure 17
0.45
Clock Pulse Width High
tPWH
Figure 17
0.45
Aperture Delay
tAD
Figure 4
100
ps
Aperture Jitter
tAJ
Figure 4
<0.5
ps
Reset Input Data Setup Time
(Note 13)
tSU
Figure 15
0
ps
Reset Input Data Hold Time
(Note 13)
tHD
Figure 15
0
ps
CLK to DREADY Propagation
Delay
tPD1
Figure 17
DREADY to DATA Propagation
Delay (Note 14)
tPD2
Figure 17
DATA Rise Time
DATA Fall Time
1
Gsps
ns
5
2.2
-50
150
ns
ns
350
ps
tRDATA
20% to 80%, CL = 3pF
420
ps
tFDATA
20% to 80%, CL = 3pF
360
ps
DREADY Rise Time
tRDREADY
20% to 80%, CL = 3pF
220
ps
DREADY Fall Time
tFDREADY
20% to 80%, CL = 3pF
Primary Port Pipeline
Delay
tPDP
Figures 6, 7, 8
Auxiliary Port Pipeline
Delay
tPDA
Figures 6, 7, 8
180
ps
DIV1, DIV2 modes
7.5
DIV4 mode
7.5
Clock
Cycles
DIV1, DIV2 modes
8.5
DIV4 mode
9.5
Clock
Cycles
Static linearity parameters are computed from a “best-fit” straight line through the code transition points. The full-scale
range (FSR) is defined as 256 · slope of the line.
Note 2: The offset control input is a self-biased voltage divider from the internal +2.5V reference voltage. The nominal open-circuit
voltage is +1.25V. It may be driven from an external potentiometer connected between REFOUT and GNDI.
Note 3: The clock input’s termination voltage can be operated between -2.0V and GNDI. Observe the absolute maximum ratings
on the CLK+ and CLK- inputs.
Note 4: Input logic levels are measured with respect to the VCCO power-supply voltage.
Note 5: All PECL digital outputs are loaded with 50Ω to VCCO - 2.0V. Measurements are made with respect to the VCCO powersupply voltage.
Note 6: The current in the VCCO power supply does not include the current in the digital output’s emitter followers, which is a function of the load resistance and the VTT termination voltage.
Note 7: Common-Mode Rejection Ratio is defined as the ratio of the change in the transfer-curve offset voltage to the change in
the common-mode voltage, expressed in dB.
Note 8: Power-Supply Rejection Ratio is defined as the ratio of the change in the transfer-curve offset voltage to the change in
power-supply voltage, expressed in dB.
Note 9: Measured with the positive supplies tied to the same potential; VCCA = VCCD = VCCI. VCC varies from +4.75V to +5.25V.
Note 10: VEE varies from -5.25V to -4.75V.
Note 1:
_______________________________________________________________________________________
5
MAX104
AC ELECTRICAL CHARACTERISTICS (continued)
Note 11: Effective Number of Bits (ENOB) and Signal-to-Noise Plus Distortion (SINAD) are computed from a curve fit referenced to
the theoretical full-scale range.
Note 12: Total Harmonic Distortion (THD) is computed from the first five harmonics.
Note 13: Guaranteed by design with a reset pulse one clock period long or greater.
Note 14: The DREADY to DATA propagation delay is measured from the 50% point on the rising edge of the DREADY signal (when
the output data changes) to the 50% point on a data output bit. This places the falling edge of the DREADY signal in the
middle of the data output valid window, within the differences between the DREADY and DATA rise and fall times, which
gives maximum setup and hold time for latching external data latches.
Typical Operating Characteristics
(VCCA = VCCI = VCCD = +5V, VEE = -5V, VCCO = +3.3V, REFIN connected to REFOUT, fS = 1Gsps, TA = +25°C, unless otherwise
noted.)
7.75
8.00
-12dBFS
7.75
-6dBFS
SINAD (dB)
-1dBFS
7.25
-1dBFS
7.25
7.00
45
6.75
6.75
44
6.50
1000 1250
100
-1dBFS
46
7.00
10
-6dBFS
47
7.50
ENOB (Bits)
43
6.50
10
100
10
1000 1250
100
1000 1250
ANALOG INPUT FREQUENCY (MHz)
ANALOG INPUT FREQUENCY (MHz)
SIGNAL-TO-NOISE PLUS DISTORTION vs.
ANALOG INPUT FREQUENCY
(DIFFERENTIAL ANALOG INPUT DRIVE)
SIGNAL-TO-NOISE RATIO vs.
ANALOG INPUT FREQUENCY
(SINGLE-ENDED ANALOG INPUT DRIVE)
SIGNAL-TO-NOISE RATIO vs.
ANALOG INPUT FREQUENCY
(DIFFERENTIAL ANALOG INPUT DRIVE)
-12dBFS
48
50
MAX104toc04
49
-1dBFS
46
-6dBFS
50
-1dBFS
46
-6dBFS
-1dBFS
-6dBFS
42
SNR (dB)
46
SNR (dB)
47
38
-12dBFS
45
34
44
43
100
1000 1250
ANALOG INPUT FREQUENCY (MHz)
42
38
-12dBFS
34
30
10
MAX104toc06
ANALOG INPUT FREQUENCY (MHz)
MAX104toc05
ENOB (Bits)
-12dBFS
48
-6dBFS
7.50
6
49
MAX104toc02
-12dBFS
MAX104toc01
8.00
SIGNAL-TO-NOISE PLUS DISTORTION vs.
ANALOG INPUT FREQUENCY
(SINGLE-ENDED ANALOG INPUT DRIVE)
EFFECTIVE NUMBER OF BITS vs.
ANALOG INPUT FREQUENCY
(DIFFERENTIAL ANALOG INPUT DRIVE)
MAX104toc03
EFFECTIVE NUMBER OF BITS vs.
ANALOG INPUT FREQUENCY
(SINGLE-ENDED ANALOG INPUT DRIVE)
SINAD (dB)
MAX104
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
30
10
100
ANALOG INPUT FREQUENCY (MHz)
1000 1250
10
100
ANALOG INPUT FREQUENCY (MHz)
_______________________________________________________________________________________
1000 1250
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
SPURIOUS-FREE DYNAMIC RANGE vs.
ANALOG INPUT FREQUENCY
(SINGLE-ENDED ANALOG INPUT DRIVE)
-1dBFS
70
7.75
-6dBFS
50
40
60
7.50
ENOB (Bits)
SFDR (dB)
-12dBFS
-12dBFS
50
30
6.75
6.50
30
1000 1250
100
10
ANALOG INPUT FREQUENCY (MHz)
EFFECTIVE NUMBER OF BITS
vs. VCCI = VCCA = VCCD
(fIN = 125MHz, -1dBFS)
DIFFERENTIAL CLOCK DRIVE
7.75
7.75
ENOB (Bits)
SINGLE-ENDED CLOCK DRIVE
7.25
MAX104-13
8.00
MAX104toc12
8.00
ENOB (Bits)
1000
CLOCK FREQUENCY (MHz)
ANALOG INPUT FREQUENCY (MHz)
EFFECTIVE NUMBER OF BITS vs.
CLOCK POWER
(fIN = 125MHz, -1dBFS)
7.50
100
1000 1250
100
7.50
7.25
7.00
7.00
6.75
6.75
6.50
6.50
-12 -10 -8 -6 -4 -2
0
2
4
6
4.50
8 10
4.70
4.90
5.10
5.30
5.50
CLOCK POWER (dBm) PER SIDE
VCC (V)
EFFECTIVE NUMBER OF BITS vs. VEE
(fIN = 125MHz, -1dBFS)
SPURIOUS-FREE DYNAMIC RANGE
vs. CLOCK POWER
(fIN = 125MHz, -1dBFS)
75
MAX104-14
8.00
7.75
MAX104toc15
10
7.25
7.00
40
73
71
SINGLE-ENDED CLOCK DRIVE
69
7.50
SFDR (dB)
ENOB (Bits)
SFDR (dB)
-6dBFS
MAX104toc11
-1dBFS
70
8.00
MAX104toc10
80
MAX104toc09
80
60
EFFECTIVE NUMBER OF BITS vs.
CLOCK FREQUENCY
(fIN = 125MHz, -1dBFS)
SPURIOUS-FREE DYNAMIC RANGE vs.
ANALOG INPUT FREQUENCY
(DIFFERENTIAL ANALOG INPUT DRIVE)
7.25
7.00
67
DIFFERENTIAL CLOCK DRIVE
65
63
61
59
6.75
57
55
6.50
-5.50
-5.30
-5.10
-4.90
VEE (V)
-4.70
-4.50
-12 -10 -8 -6 -4 -2
0
2
4
6
8 10
CLOCK POWER (dBm) PER SIDE
_______________________________________________________________________________________
7
MAX104
Typical Operating Characteristics (continued)
(VCCA = VCCI = VCCD = +5V, VEE = -5V, VCCO = +3.3V, REFIN connected to REFOUT, fS = 1Gsps, TA = +25°C, unless otherwise
noted.)
Typical Operating Characteristics (continued)
(VCCA = VCCI = VCCD = +5V, VEE = -5V, VCCO = +3.3V, REFIN connected to REFOUT, fS = 1Gsps, TA = +25°C, unless otherwise
noted.)
74
72
72
71
71
70
69
70
69
68
68
67
67
66
66
65
4.70
4.90
5.10
5.30
-76.8
-128.0
-5.50
-5.30
-5.10
-4.90
-4.70
0
-4.50
100
200
300
400
500
VCC (V)
VEE (V)
ANALOG INPUT FREQUENCY (MHz)
FFT PLOT
(fIN = 494.5068MHz, RECORD LENGTH 8192)
FFT PLOT
(fIN = 1005.0049MHz, RECORD LENGTH 8192)
TWO-TONE INTERMODULATION
FFT PLOT (fIN1 = 124MHz, fIN2 = 126MHz,
7dB BELOW FULL-SCALE, RECORD LENGTH 8192)
-76.8
-102.4
-51.2
-76.8
-102.4
-128.0
100
200
300
400
500
fIN1
-51.2
-76.8
-102.4
-128.0
-128.0
0
100
200
300
400
500
0
100
200
300
400
500
ANALOG INPUT FREQUENCY (MHz)
ANALOG INPUT FREQUENCY (MHz)
ANALOG INPUT FREQUENCY (MHz)
ANALOG INPUT BANDWIDTH
-6dB BELOW FULL-SCALE
ANALOG INPUT BANDWIDTH
FULL-POWER
INTEGRAL NONLINEARITY
vs. OUTPUT CODE
(LOW-FREQUENCY SERVO LOOP DATA)
0.3
0.2
-2
INL (LSB)
AMPLITUDE (dB)
-8
0.4
-1
-6
-7
0.5
MAX104toc24
0
MAX104toc22
-5
MAX104toc23
0
fIN2
-25.6
AMPLITUDE (dB)
-51.2
0
MAX104toc21
ENOB = 7.51 BITS
SNR = 46.3dB
THD = -52.8dB
SFDR = 53.7dB
-25.6
AMPLITUDE (dB)
-25.6
0
MAX104toc20
ENOB = 7.51 BITS
SNR = 46.8dB
THD = -51.9dB
SFDR = 52.1dB
MAX104toc19
0
AMPLITUDE (dB)
5.50
-51.2
-102.4
65
4.50
ENOB = 7.75 BITS
SNR = 47.4dB
THD = -66.2dB
SFDR = 70.3dB
-25.6
AMPLITUDE (dB)
73
SFDR (dB)
73
0
MAX104-17
74
SFDR (dB)
75
MAX104-16
75
FFT PLOT
(fIN = 125.8545MHz, RECORD LENGTH 8192)
SPURIOUS-FREE DYNAMIC RANGE vs. VEE
(fIN = 125MHz, -1dBFS)
MAX104toc18
SPURIOUS-FREE DYNAMIC RANGE
vs. VCCI = VCCA = VCCD
(fIN = 125MHz, -1dBFS)
AMPLITUDE (dB)
MAX104
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
-3
0.1
0
-0.1
-0.2
-4
-9
-0.4
-5
-10
500
1500 2500
ANALOG INPUT FREQUENCY (MHz)
8
-0.3
FULL-POWER BANDWIDTH = 2.2GHz
SMALL-SIGNAL BANDWIDTH = 2.4GHz
500
1500 2500
ANALOG INPUT FREQUENCY (MHz)
-0.5
0
32
64
96
128 160 192 224
OUTPUT CODE
_______________________________________________________________________________________
256
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
0.4
0.3
1.4
DREADY
(200mV/div)
VSWR
0.2
0.1
0
1.3
1.2
-0.1
-0.2
DATA
(200mV/div)
-0.3
1.1
-0.4
1.0
-0.5
0
0
32
64
96
128 160 192 224
256
500
500ps/div
2000
2500
-61
-62
-63
-63
-64
-64
THD (dB)
-62
-65
-66
-65
-66
-67
-67
-68
-68
-69
-69
-70
MAX104-29
-60
MAX104-28
-61
1500
TOTAL HARMONIC DISTORTION
vs. VCCI = VCCA = VCCD
(fIN = 125MHz, -1dBFS)
TOTAL HARMONIC DISTORTION vs. VEE
(fIN = 125MHz, -1dBFS)
-60
1000
ANALOG INPUT FREQUENCY (MHz)
OUTPUT CODE
THD (dB)
DNL (LSB)
VSWR vs. ANALOG INPUT FREQUENCY
1.5
MAX104toc26
MAX104toc25
0.5
DREADY RISE/FALL TIME,
DATA OUTPUT RISE/FALL TIME
MAX104toc27
DIFFERENTIAL NONLINEARITY
vs. OUTPUT CODE
(LOW-FREQUENCY SERVO LOOP DATA)
-70
-5.50
-5.30
-5.10
-4.90
-4.70
-4.50
4.50
4.70
4.90
VEE (V)
5.10
5.30
5.50
VCC (V)
Pin Description
CONTACT
NAME
FUNCTION
A1–A4, A6, A7, B1, B2, C1, C2, D1, D2,
D3, G1, H1, J2, J3, K1–K3, L2, L3, M1,
N1, T2, T3, U1, V1, V2, W1–W4
GNDI
Analog Ground. For T/H amplifier, clock distribution, bandgap
reference, and reference amplifier.
A5, B5, C5, H2, H3, M2, M3, U5, V5, W5
VCCI
Analog Supply Voltage, +5V. Supplies T/H amplifier, clock distribution, bandgap reference, and reference amplifier.
A8, B8, C8, U6, V6, W6
GNDA
Analog Ground. For comparator array.
A9, B9, C9, U7, V7, W7
VCCA
Analog Supply Voltage, +5V. Supplies analog comparator array.
Test Point. Do not connect.
A10, E17, F2, P3, R17, R18
TESTPOINT (T.P.)
A11, B11, B16, B17, C11, C16, U9, U17,
V9, V17, V18, W9
GNDD
Digital Ground
A12–A19, B19, C19, D19, E19, F19,
G19, H19, J19, K19, L19, M19, N19,
P19, T19, U19, V19, W10-W19
VCCO
PECL Supply Voltage, +3V to +5V
_______________________________________________________________________________________
9
MAX104
Typical Operating Characteristics (continued)
(VCCA = VCCI = VCCD = +5V, VEE = -5V, VCCO = +3.3V, REFIN connected to REFOUT, fS = 1Gsps, TA = +25°C, unless otherwise
noted.)
MAX104
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
Pin Description (continued)
CONTACT
NAME
FUNCTION
B3, B4, C3, C4, E3, F3, G2, G3, N2, N3,
U2, U3, U4, V3, V4
VEE
Analog Supply Voltage, -5V. Supplies T/H amplifier, clock distribution, bandgap reference, and reference amplifier.
B6, B7
GNDR
Reference Ground. Must be connected to GNDI.
B10, B18, C10, C17, C18, T17, T18, U8,
U18, V8, W8
VCCD
Digital Supply Voltage, +5V
B12
P0+
Primary Output Data Bit 0 (LSB)
B13
A0+
Auxiliary Output Data Bit 0 (LSB)
B14
P1+
Primary Output Data Bit 1
B15
A1+
Auxiliary Output Data Bit 1
C6
REFIN
10
Reference Input
C7
REFOUT
C12
P0-
Reference Output
Complementary Primary Output Data Bit 0 (LSB)
C13
A0-
Complementary Auxiliary Output Data Bit 0 (LSB)
C14
P1-
Complementary Primary Output Data Bit 1
C15
A1-
Complementary Auxiliary Output Data Bit 1
D17
DIVSELECT
D18
AUXEN2
Tie to VCCO to power the auxiliary port. Tie to GNDD to power
down.
E1
ICONST
Die Temperature Measurement Test Point. See Die Temperature
Measurement section.
E2
IPTAT
Die Temperature Measurement Test Point. See Die Temperature
Measurement section.
E18
DEMUXEN
F1
VOSADJ
F17
P2-
Complementary Primary Output Data Bit 2
F18
P2+
Primary Output Data Bit 2
G17
A2-
Complementary Auxiliary Output Data Bit 2
G18
A2+
Auxiliary Output Data Bit 2
H17
P3-
Complementary Primary Output Data Bit 3
H18
P3+
Primary Output Data Bit 3
TTL/CMOS Demux Divide Selection Input
1: Decimation DIV4 mode
0: Demultiplexed DIV2 mode
TTL/CMOS Demux Enable Control
1: Enable Demux
0: Disable Demux
Offset Adjust Input
______________________________________________________________________________________
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
CONTACT
NAME
FUNCTION
J1
VIN-
Differential Input Voltage (-)
J17
A3-
Complementary Auxiliary Output Data Bit 3
J18
A3+
Auxiliary Output Data Bit 3
K17
DREADY-
Complementary Data-Ready Clock
K18
DREADY+
Data-Ready Clock
L1
VIN+
Differential Input Voltage (+)
L17
P4-
Complementary Primary Output Data Bit 4
L18
P4+
Primary Output Data Bit 4
M17
A4-
Complementary Auxiliary Output Data Bit 4
M18
A4+
Auxiliary Output Data Bit 4
N17
P5-
Complementary Primary Output Data Bit 5
N18
P5+
Primary Output Data Bit 5
P1
CLK-
Complementary Sampling-Clock Input
P2
TESTPOINT (T.P.)
This contact must be connected to GNDI.
P17
A5-
Complementary Auxiliary Output Data Bit 5
Auxiliary Output Data Bit 5
P18
A5+
R1, R2, R3
CLKCOM
50Ω Clock Termination Return
R19
AUXEN1
Tie to VCCO to power the auxiliary port. Tie to GNDD to power
down.
T1
CLK+
Sampling Clock Input
U10
RSTIN-
Complementary PECL Demux Reset Input
U11
RSTOUT-
Complementary PECL Reset Output
U12
OR-
Complementary PECL Overrange Bit
U13
A7-
Complementary Auxiliary Output Data Bit 7 (MSB)
U14
P7-
Complementary Primary Output Data Bit 7 (MSB)
U15
A6-
Complementary Auxiliary Output Data Bit 6
U16
P6-
Complementary Primary Output Data Bit 6
V10
RSTIN+
V11
RSTOUT+
PECL Reset Output
V12
OR+
PECL Overrange Bit
V13
A7+
Auxiliary Output Data Bit 7 (MSB)
V14
P7+
Primary Output Data Bit 7 (MSB)
V15
A6+
Auxiliary Output Data Bit 6
V16
P6+
Primary Output Data Bit 6
PECL Demux Reset Input
______________________________________________________________________________________
11
MAX104
Pin Description (continued)
MAX104
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
REF REF
OUT IN
BANDGAP
REFERENCE
REFERENCE
AMPLIFIER
+2.5V
GNDR
VOSADJ
DIFFERENTIAL
PECL OUTPUTS
MAX104
BIAS CURRENTS
OVERRANGE
BIT
GNDI
OR
2
50Ω
T/H AMPLIFIER
VIN+
VIN-
AUXILIARY
DATA PORT
2
8-BIT
FLASH ADC
16
50Ω
GNDI
CLK+
CLKCOM
50Ω
CLK-
RSTIN+
RSTIN-
PRIMARY
DATA PORT
16
DATA
READY CLOCK
2
DEMUX
RESET OUTPUT
2
LOGIC
CLOCK
DRIVER
50Ω
T/H
CLOCK
DRIVER
RESET INPUT
DUAL LATCH
A0–A7
16
P0–P7
DREADY
DEMUX
CLOCK
DRIVER
ADC
CLOCK
DRIVER
RESET
PIPELINE
DELAYED
RESET
DEMUX
CLOCK
GENERATOR
RSTOUT
DEMUXEN DIVSELECT
Figure 1. Simplified Functional Diagram
_______________Detailed Description
The MAX104 is an 8-bit, 1Gsps flash analog-to-digital
converter (ADC) with on-chip track/hold (T/H) amplifier
and differential PECL-compatible outputs. The ADC
(Figure 1) employs a fully differential 8-bit quantizer
and a unique encoding scheme to limit metastable
states to typically one error per 1016 clock cycles, with
no error exceeding 1LSB max.
An integrated 8:16 output demultiplexer simplifies interfacing to the part by reducing the output data rate to
one-half the sampling clock rate. This demultiplexer
has internal reset capability that allows multiple
12
MAX104s to be time-interleaved to achieve higher
effective sampling rates.
When clocked at 1Gsps, the MAX104 provides a typical effective number of bits (ENOB) of >7.5 bits at an
analog input frequency of 500MHz. The analog input of
the MAX104 is designed for differential or single-ended
use with a ±250mV full-scale input range. In addition,
this ADC features an on-chip +2.5V precision bandgap
reference. If desired, an external reference can also be
used.
______________________________________________________________________________________
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
MAX104
Principle of Operation
OVERRANGE + 255
255
254
DIGITAL OUTPUT
129
128
127
126
3
2
1
0
The T/H amplifier buffers the input signal and allows a
full-scale signal input range of ±250mV. The T/H amplifier’s differential 50Ω input termination simplifies interfacing to the MAX104 with controlled impedance lines.
Figure 3 shows a simplified diagram of the T/H amplifier
stage internal to the MAX104.
Aperture width, delay, and jitter (or uncertainty) are
parameters that affect the dynamic performance of
high-speed converters. Aperture jitter, in particular,
directly influences SNR and limits the maximum slew
rate (dV/dt) that can be digitized without contributing
significant errors. The MAX104’s innovative T/H amplifier
design limits aperture jitter typically to less than 0.5ps.
Aperture Width
Aperture width (tAW) is the time the T/H circuit requires
(Figure 4) to disconnect the hold capacitor from the
input circuit (for instance, to turn off the sampling
bridge and put the T/H unit in hold mode).
Aperture Jitter
Aperture jitter (tAJ) is the sample-to-sample variation
(Figure 4) in the time between the samples.
Aperture Delay
Aperture delay (tAD) is the time defined between the
rising edge of the sampling clock and the instant when
an actual sample is taken (Figure 4).
Internal Reference
The MAX104 features an on-chip +2.5V precision
bandgap reference, which can be used by connecting
(+FS - 1LSB)
+FS
On-Chip Track/Hold Amplifier
As with all ADCs, if the input waveform is changing
rapidly during conversion, effective number of bits
(ENOB) and signal-to-noise ratio (SNR) specifications
will degrade. The MAX104’s on-chip, wide-bandwidth
(2.2GHz) T/H amplifier reduces this effect and increases
the ENOB performance significantly, allowing precise
capture of fast analog data at high conversion rates.
0
(-FS + 1LSB)
The MAX104’s flash or parallel architecture provides
the fastest multibit conversion of all common integrated
ADC designs. The key to this high-speed flash architecture is the use of an innovative, high-performance
comparator design. The flash converter and downstream logic translate the comparator outputs into a
parallel 8-bit output code and pass this binary code on
to the optional 8:16 demultiplexer, where primary and
auxiliary ports output PECL-compatible data at up to
500Msps per port (depending on how the demultiplexer section is set on the MAX104).
The ideal transfer function appears in Figure 2.
ANALOG INPUT
Figure 2. Transfer Function
ALL INPUTS ARE ESD PROTECTED
(NOT SHOWN IN THIS
INPUT
SAMPLING
SIMPLIFIED DRAWING).
AMPLIFIER
BRIDGE
BUFFER
AMPLIFIER
VIN+
VIN-
TO
COMPARATORS
50Ω
50Ω
CHOLD
GNDI
GNDI
CLK+
CLK-
CLOCK
SPLITTER
50Ω
TO
COMPARATORS
50Ω
CLKCOM
Figure 3. Internal Structure of the 2.2GHz T/H Amplifier
CLK
CLK
tAW
ANALOG
INPUT
tAD
tAJ
SAMPLED
DATA (T/H)
T/H
TRACK
HOLD
TRACK
APERTURE DELAY (tAD)
APERTURE WIDTH (tAW)
APERTURE JITTER (tAJ)
Figure 4. T/H Aperture Timing
______________________________________________________________________________________
13
MAX104
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
REFOUT to REFIN. This connects the reference output
to the positive input of the reference buffer. The buffer’s
negative input is internally connected to GNDR. GNDR
must be connected to GNDI on the user’s application
board. REFOUT can source up to 2.5mA to supply
external devices if required.
An adjustable external reference can be used to adjust
the ADC’s full-scale range. To use an external reference supply, simply connect a high-precision reference
to the REFIN pin and leave the REFOUT pin floating. In
this configuration, REFOUT must not be simultaneously
connected to avoid conflicts between the two references. REFIN has a typical input resistance of 5kΩ and
accepts input voltages of +2.5V ±200mV. Using the
MAX104’s internal reference is recommended for best
performance.
Digital Outputs
The MAX104 provides data in offset binary format to differential PECL outputs. A simplified circuit schematic of
the PECL output cell is shown in Figure 5. All PECL outputs are powered from VCCO, which may be operated
from any voltage between +3.0V to VCCD for flexible
interfacing with either +3.3V or +5V systems. The nominal VCCO supply voltage is +3.3V.
All PECL outputs on the MAX104 are open-emitter
types and must be terminated at the far end of each
transmission line with 50Ω to VCCO - 2V. Table 1 lists all
MAX104 PECL outputs and their functions.
VCCO
500Ω
500Ω
A_+/P_+
DIFF.
PAIR
GNDD
A_-/P_-
1.8mA
GNDD
GNDD
Figure 5. Simplified PECL Output Structure
Demultiplexer Operation
The MAX104 features an internal data demultiplexer
that provides for three different modes of operation (see
the following sections on Demultiplexed DIV2 Mode,
Non-Demultiplexed DIV1 Mode, and Decimation DIV4
Mode) controlled by two TTL/CMOS-compatible inputs:
DEMUXEN and DIVSELECT.
DEMUXEN enables or disables operation of the internal
1:2 demultiplexer. A logic high on DEMUXEN activates
the internal demultiplexer, and a logic low deactivates
it. With the internal demultiplexer enabled, DIVSELECT
controls the selection of the operational mode. DIVSELECT low selects demultiplexed DIV2 mode, and DIVSELECT high selects decimation DIV4 mode (Table 2).
Table 1. PECL Output Functions
PECL OUTPUT SIGNALS
P0+, P0-, P1+, P1-, P2+, P2-,
P3+, P3-, P4+, P4-, P5+, P5-,
P6+, P6-, P7+, P7-
Primary-Port Differential Outputs from LSB to MSB. A “+” indicates the true outputs; a “-”
denotes the complementary outputs.
A0+, A0-, A1+, A1-, A2+, A2-,
A3+, A3-, A4+, A4-, A5+, A5-,
A6+, A6-, A7+, A7-
Auxiliary-Port Differential Outputs from LSB to MSB. A “+” indicates the true outputs; a “-”
denotes the complementary outputs.
DREADY+, DREADYOR+, ORRSTOUT+, RSTOUT14
FUNCTIONAL DESCRIPTION
Data-Ready Clock True and Complementary Outputs. These signal lines are used to latch
the output data from the primary to the auxiliary output ports. Data changes on the rising
edge of the DREADY clock.
Overrange True and Complementary Outputs
Reset Output True and Complementary Outputs
______________________________________________________________________________________
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
ADC SAMPLE NUMBER
CLKCLK
n
n+1
n+2
PECL termination power supply (VCCO - 2V) may be
removed from all auxiliary output ports.
Demultiplexed DIV2 Mode
The MAX104 features an internally selectable DIV2
mode (Table 2) that reduces the output data rate to
one-half of the sample clock rate. The demultiplexed
outputs are presented in dual 8-bit format with two consecutive samples appearing in the primary and auxiliary output ports on the rising edge of the data-ready
clock (Figure 7). The auxiliary data port contains the
previous sample, and the primary output contains the
most recent data sample. AUXEN1 and AUXEN2 must
be connected to VCCO to power-up the auxiliary port
PECL output drivers.
ADC SAMPLES ON THE RISING EDGE OF CLK+
n+3
n+4
n+5
n+6
n+7
n+8
n+9
n+10
n+11
n+12
n+13
AUXILIARY
DATA PORT
n
n+1
n+2
n+3
n+4
PRIMARY
DATA PORT
n+1
n+2
n+3
n+4
n+5
n+10
n+11
n+12
n+13
CLK+
DREADY+
DREADY
DREADY-
NOTE: THE AUXILIARY PORT DATA IS DELAYED ONE ADDITIONAL CLOCK CYCLE FROM THE PRIMARY PORT DATA.
GROUNDING AUXEN1 AND AUXEN2 WILL POWER DOWN THE AUXILIARY PORT TO SAVE POWER.
Figure 6. Non-Demuxed, DIV1-Mode Timing Diagram
ADC SAMPLE NUMBER
CLKCLK
n
n+1
n+2
ADC SAMPLES ON THE RISING EDGE OF CLK+
n+3
n+4
n+5
n+6
n+7
n+8
n+9
CLK+
DREADY+
DREADY
DREADYAUXILIARY
DATA PORT
n-1
n+1
n+3
PRIMARY
DATA PORT
n
n+2
n+4
NOTE: THE LATENCY TO THE PRIMARY PORT IS 7.5 CLOCK CYCLES, AND THE LATENCY TO THE AUXILIARY PORT IS 8.5 CLOCK CYCLES.
BOTH THE PRIMARY AND AUXILIARY DATA PORTS ARE UPDATED ON THE RISING EDGE OF THE DREADY+ CLOCK.
Figure 7. Demuxed DIV2-Mode Timing Diagram
______________________________________________________________________________________
15
MAX104
Non-Demultiplexed DIV1 Mode
The MAX104 may be operated at up to 500Msps in nondemultiplexed DIV1 mode (Table 2). In this mode, the
internal demultiplexer is disabled, and sampled data is
presented to the primary port only, with the data repeated at the auxiliary port but delayed by one clock cycle
(Figure 6). Since the auxiliary output port contains the
same data stream as the primary output port, the auxiliary port can be shut down to save power by connecting
AUXEN1 and AUXEN2 to digital ground (GNDD). This
powers down the internal bias cells and causes both
outputs (true and complementary) of the auxiliary port to
pull up to a logic-high level. To save additional power,
the external 50Ω termination resistors connected to the
MAX104
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
Decimation DIV4 Mode
The MAX104 also offers a special decimated, demultiplexed output (Figure 8) that discards every other input
sample and outputs data at one-quarter the input sampling rate for system debugging at slower output data
rates. With an input clock of 1GHz, the effective output
data rate will be reduced to 250MHz per output port in
the DIV4 mode (Table 2). Since every other sample is
discarded, the effective sampling rate is 500Msps.
the OR bit will flag an overrange condition if either the
primary or auxiliary port contains an overranged sample (Table 2). In non-demultiplexed DIV1 mode, the OR
port will flag an overrange condition only when the primary output port contains an overranged sample.
Applications Information
Single-Ended Analog Inputs
The MAX104 T/H amplifier is designed to work at full
speed for both single-ended and differential analog
inputs (Figure 9). Inputs VIN+ and VIN- feature on-chip,
laser-trimmed 50Ω termination resistors to provide
excellent voltage standing wave ratio (VSWR) performance.
Overrange Operation
A single differential PECL overrange output bit (OR+,
OR-) is provided for both primary and auxiliary demultiplexed outputs. The operation of the overrange bit
depends on the status of the internal demultiplexer. In
demultiplexed DIV2 mode and decimation DIV4 mode,
ADC SAMPLE NUMBER
CLK-
n
n+1
n+2
ADC SAMPLES ON THE RISING EDGE OF CLK+
n+3
n+4
n+5
n+6
n+7
n+8
n+9
n+10
n+11
n+12
n+13
CLK
CLK+
DREADY+
DREADY
DREADYAUXILIARY
DATA PORT
n-2
n+2
PRIMARY
DATA PORT
n
n+4
NOTE: THE LATENCY TO THE PRIMARY PORT REMAINS 7.5 CLOCK CYCLES, WHILE THE LATENCY OF THE AUXILIARY PORT INCREASES TO 9.5 CLOCK CYCLES.
THIS EFFECTIVELY DISCARDS EVERY OTHER SAMPLE AND REDUCES THE OUTPUT DATA RATE TO 1/4 THE SAMPLE CLOCK RATE.
Figure 8. Decimation DIV4-Mode Timing Diagram
Table 2. Demultiplexer Operation
DEMUXEN
DIVSELECT
DEMUX MODE
OVERRANGE BIT OPERATION
Low
X
DIV1
500Msps (max)
Flags overrange data appearing in primary
port only.
High
Low
DIV2
500Msps/port
High
DIV4
250Msps/port
High
Flags overrange data appearing in either
the primary or auxiliary port.
X = Don’t care
16
______________________________________________________________________________________
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
MAX104
ANALOG INPUTS ARE ESD PROTECTED
(NOT SHOWN IN THIS SIMPLIFIED DRAWING).
+2.8V
VIN+
+250mV
VIN+
500mVp-p
FS ANALOG
INPUT RANGE
50Ω
500mV
OV
VIN-
GNDI
-250mV
t
VIN = ±250mV
50Ω
VIN-
Figure 10a. Single-Ended Analog Input Signals
VEE
Figure 9. Simplified Analog Input Structure (Single-Ended/
Differential)
In a typical single-ended configuration, the analog
input signal (Figure 10a) enters the T/H amplifier stage
at the in-phase input (VIN+), while the inverted phase
input (VIN-) is reverse-terminated to GNDI with an
external 50Ω resistor. Single-ended operation allows for
an input amplitude of ±250mV. Table 3 shows a selection of input voltages and their corresponding output
codes for single-ended operation.
Differential Analog Inputs
To obtain a full-scale digital output with differential input
drive (Figure 10b), 250mVp-p must be applied between
VIN+ and VIN- (VIN+ = +125mV and VIN- = -125mV).
Midscale digital output codes (01111111 or 10000000)
occur when there is no voltage difference between
VIN+ and VIN-. For a zero-scale digital output code, the
VIN+
VIN-
+125mV
±250mV
FS ANALOG
INPUT RANGE
250mV
-250mV
-125mV
OV
t
Figure 10b. Differential Analog Input Signals
in-phase (VIN+) input must see -125mV and the inverted input (VIN-) must see +125mV. A differential input
drive is recommended for best performance. Table 4
represents a selection of differential input voltages and
their corresponding output codes.
Table 3. Ideal Input Voltage and Output Code Results for Single-Ended Operation
VIN+
VIN-
OVERRANGE BIT
OUTPUT CODE
+250mV
0V
1
11111111 (full scale)
+250mV - 1LSB
0V
0
11111111
0V
0V
0
01111111
toggles
10000000
-250mV + 1LSB
0V
0
0000001
-250mV
0V
0
00000000 (zero scale)
______________________________________________________________________________________
17
MAX104
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
Table 4. Ideal Input Voltage and Output Code Results for Differential Operation
VIN+
VIN-
OVERRANGE BIT
OUTPUT CODE
+125mV
-125mV
1
11111111 (full scale)
+125mV - 0.5LSB
-125mV + 0.5LSB
0
11111111
0V
0V
0
01111111
toggles
10000000
-125mV + 0.5LSB
+125mV - 0.5LSB
0
00000001
-125mV
+125mV
0
00000000 (zero scale)
Offset Adjust
The MAX104 provides a control input (VOSADJ) to compensate for system offsets. The offset adjust input is a
self-biased voltage divider from the internal +2.5V precision reference. The nominal open-circuit voltage is onehalf the reference voltage. With an input resistance of
typically 25kΩ, this pin may be driven by an external
10kΩ potentiometer (Figure 11) connected between
REFOUT and GNDI to correct for offset errors. This control provides a typical ±5.5LSB offset adjustment range.
Clock Operation
The MAX104 clock inputs are designed for either singleended or differential operation (Figure 12) with flexible
input drive requirements. Each clock input is terminated
with an on-chip, laser-trimmed 50Ω resistor to CLKCOM
(clock-termination return). The CLKCOM termination
voltage can be connected anywhere between ground
and -2V for compatibility with standard ECL drive levels.
The clock inputs are internally buffered with a preamplifier to ensure proper operation of the data converter
with even small-amplitude sine-wave sources. The
MAX104 was designed for single-ended, low-phasenoise sine-wave clock signals with as little as 100mV
amplitude (-10dBm). This eliminates the need for an
external ECL clock buffer and its added jitter.
Single-Ended Clock Inputs (Sine-Wave Drive)
Excellent performance is obtained by AC- or DC-coupling a low-phase-noise sine-wave source into a single
clock input (Figure 13a, Table 5). For proper DC balance, the undriven clock input should be externally
50Ω reverse-terminated to GNDI.
The dynamic performance of the data converter is
essentially unaffected by clock-drive power levels from
REFOUT
MAX104
POT
10k
VOSADJ
GNDI
Figure 11. Offset Adjust with External 10kΩ Potentiometer
CLK+
50Ω
+0.8V
CLKCOM
50Ω
GNDI
CLK-
CLOCK INPUTS ARE
ESD PROTECTED
(NOT SHOWN IN THIS
SIMPLIFIED DRAWING).
Figure 12. Simplified Clock Input Structure (Single-Ended/
Differential)
18
______________________________________________________________________________________
VEE
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
Differential Clock Inputs (Sine-Wave Drive)
The advantages of differential clock drive (Figure 13b,
Table 5) can be obtained by using an appropriate
balun or transformer to convert single-ended sine-wave
sources into differential drives. The precision on-chip,
laser-trimmed 50Ω clock-termination resistors ensure
excellent amplitude matching. Refer to Single-Ended
Clock Inputs (Sine-Wave Drive) for proper input amplitude requirements.
Single-Ended Clock Inputs (ECL Drive)
Configure the MAX104 for single-ended ECL clock drive
by connecting the clock inputs as shown in Figure 13c
(Table 5). A well bypassed VBB supply (-1.3V) is essential to avoid coupling noise into the undriven clock input,
which would degrade dynamic performance.
Differential Clock Inputs (ECL Drive)
The MAX104 may be driven from a standard differential
(Figure 13d, Table 5) ECL clock source by setting the
clock termination voltage at CLKCOM to -2V. Bypass
the clock-termination return (CLKCOM) as close as
possible to the ADC with a 0.01µF capacitor connected
to GNDI.
AC-Coupling Clock Inputs
The clock inputs CLK+ and CLK- can also be driven
with positive referenced ECL (PECL) logic if the clock
CLK+
CLK+
+0.5V
CLK-
+0.5V
CLK- = 0V
-0.5V
t
NOTE: CLKCOM = 0V
-0.5V
NOTE: CLKCOM = 0V
Figure 13a. Single-Ended Clock Input Signals
Figure 13b. Differential Clock Input Signals
CLK+
CLK+
-0.8V
t
-0.8V
CLK-
CLK- = -1.3V
-1.8V
t
NOTE: CLKCOM = -2V
Figure 13c. Single-Ended ECL Clock Drive
-1.8V
t
NOTE: CLKCOM = -2V
Figure 13d. Differential ECL Clock Drive
______________________________________________________________________________________
19
MAX104
-10dBm (100mV clock signal amplitude) to +10dBm
(1V clock signal amplitude). The MAX104 dynamic performance specifications are determined by a singleended clock drive of +4dBm (500mV clock signal
amplitude). To avoid saturation of the input amplifier
stage, limit the clock power level to a maximum of
+10dBm.
MAX104
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
Table 5. DC-Coupled Clock Drive Options
CLOCK DRIVE
CLK+
CLK-
CLKCOM
REFERENCE
Single-Ended Sine Wave
-10dBm to +4dBm
External 50Ω to GNDI
GNDI
Figure 13a
Differential Sine Wave
-10dBm to +4dBm
-10dBm to +4dBm
GNDI
Figure 13b
Single-Ended ECL
ECL Drive
-1.3V
-2V
Figure 13c
Differential ECL
ECL Drive
ECL Drive
-2V
Figure 13d
inputs are AC-coupled. Under this condition, connect
CLKCOM to GNDI. Single-ended ECL/PECL/sine-wave
drive is also possible if the undriven clock input is
reverse-terminated to GNDI through a 50Ω resistor in
series with a capacitor whose value is identical to that
used to couple the driven input.
VCCO
Demux Reset Operation
The MAX104 features an internal 1:2 demultiplexer that
reduces the data rate of the output digital data to onehalf the sample clock rate. Demux reset is necessary
when interleaving multiple MAX104s and/or synchronizing external demultiplexers. The simplified block diagram
of Figure 1 shows that the demux reset signal path consists of four main circuit blocks. From input to output,
they are the reset input dual latch, the reset pipeline, the
demux clock generator, and the reset output. The signals associated with the demux reset operation and the
control of this section are listed in Table 6.
Reset Input Dual Latch
The reset input dual-latch circuit block accepts differential PECL reset inputs referenced to the same VCCO
power supply that powers the MAX104 PECL outputs.
For applications that do not require a synchronizing
reset, the reset inputs can be left open. In this case,
they will self-bias to a proper level with internal 50kΩ
resistors and 20µA current source. This combination
creates a -1V difference between RSTIN+ and RSTINto disable the internal reset circuitry. When driven with
PECL logic levels terminated with 50Ω to (VCCO - 2V),
the internal biasing network can easily be overdriven.
Figure 14 shows a simplified schematic of the reset
input structure.
To properly latch the reset input data, the setup time
(tSU) and the data hold time (tHD) must be met with
respect to the rising edge of the sample clock. The timing diagram of Figure 15 shows the timing relationship
of the reset input and sampling clock.
50k
50k
RSTIN+
RSTIN-
20µA
RESET INPUTS ARE
ESD PROTECTED
(NOT SHOWN IN THIS
SIMPLIFIED DRAWING).
GNDD
Figure 14. Simplified Reset Input Structure
RSTIN+
50%
50%
RSTIN-
tSU
tHD
CLK+
50%
CLK-
Figure 15. Reset Input Timing Definitions
20
______________________________________________________________________________________
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
SIGNAL NAME
TYPE
FUNCTION
CLK+, CLK-
Sampling clock inputs
Master ADC timing signal. The ADC samples on the rising edge of CLK+.
DREADY+, DREADY-
Differential PECL outputs
Data-Ready PECL Output. Output data changes on the rising edge of
DREADY+.
RSTIN+, RSTIN-
Differential PECL inputs
Demux reset input signals. Resets the internal demux when asserted.
RSTOUT+, RSTOUT-
Differential PECL outputs
Reset outputs for resetting additional external demux devices
Reset Pipeline
The next section in the reset signal path is the reset
pipeline. The purpose of this block is to add clock
cycles of latency to the reset signal, to match the latency of the converted analog data through the ADC. In
this way, when reset data arrives at the RSTOUT+/
RSTOUT- PECL output, it will be time-aligned with the
analog data present in the primary and auxiliary ports
at the time the reset input was deasserted at RSTIN+/
RSTIN-.
Demux Clock Generator
The demux clock generator creates the DIV1, DIV2, or
DIV4 clocks required for the different modes of demux
and non-demux operation. The TTL/CMOS control
inputs DEMUXEN and DIVSELECT control the demuxed
mode selection, as described in Table 2. The timing
diagrams in Figure 16 and Figure 17 show the output
timing and data alignment in DIV1, DIV2, and DIV4
modes, respectively.
The phase relationship between the sampling clock at
the CLK+/CLK- inputs and the data-ready clock at the
DREADY+/DREADY- outputs will be random at device
power-up. As with all divide-by-two circuits, two possible phase relationships exist between these clocks.
The difference between the phases is simply the inversion of the DIV2-DREADY clock. The timing diagram in
Figure 16 shows this relationship.
Reset all MAX104 devices to a known DREADY phase
after initial power-up for applications such as interleaving, where two or more MAX104 devices are used to
achieve higher effective sampling rates. This synchronization is necessary to set the order of output samples
between the devices. Resetting the converters accomplishes this synchronization. The reset signal is used to
force the internal counter in the demux clock-generator
block to a known phase state.
tPWH
CLK+
CLK+
CLK-
CLK-
50%
tPWL
tPD1
tPD1
DREADY +
DREADY"PHASE 1"
DREADY+
DREADY -
50%
tPD2
tFDREADY
tRDREADY
DREADY +
AUXILIARY PORT DATA
80%
"PHASE 2"
80%
20%
20%
DREADY PRIMARY PORT DATA
Figure 16. CLK and DREADY Timing in Demuxed DIV2 Mode
Showing Two Possible DREADY Phases
Figure 17. Output Timing for All Modes (DIV1, DIV2, DIV4)
______________________________________________________________________________________
21
MAX104
Table 6. Demux Operating and Reset Control Signal
MAX104
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
Reset Output
Finally, the reset signal is presented in differential PECL
format to the last block of the reset signal path.
RSTOUT+/RSTOUT- output the time-aligned reset signal used for resetting additional external demuxes in
applications that need further output data rate reduction. Many demux devices require that their reset signal
be asserted for several clock cycles while they are
clocked. To accomplish this, the MAX104 DREADY
clock will continue to toggle while RSTOUT is asserted.
When a single MAX104 device is used, no synchronizing reset is required, because the order of the samples
in the output ports is unchanged regardless of the
phase of the DREADY clock. In DIV2 mode, the data in
the auxiliary port is delayed by 8.5 clock cycles, while
the data in the primary port is delayed by 7.5 clock
cycles. The older data is always in the auxiliary port,
regardless of the phase of the DREADY clock.
The reset output signal, RSTOUT, is delayed by one
less clock cycle (6.5 clock cycles) than the primary
ADC SAMPLE NUMBER
CLKCLK
CLK+
RESET
INPUT
n
n+1
n+2
tSU
RSTIN-
port. The reduced latency of RSTOUT serves to mark
the start of synchronized data in the primary and auxiliary ports. When the RSTOUT signal returns to a zero,
the DREADY clock phase is reset.
Since there are two possible phases of the DREADY
clock with respect to the input clock, there are two possible timing diagrams to consider. The first timing diagram (Figure 18) shows the RSTOUT timing and data
alignment of the auxiliary and primary output ports
when the DREADY clock phase is already reset. For
this example, the RSTIN pulse is two clock cycles long.
Under this condition, the DREADY clock continues
uninterrupted, as does the data stream in the auxiliary
and primary ports.
The second timing diagram (Figure 19) shows the
results when the DREADY phase is opposite from the
reset phase. In this case, the DREADY clock “swallows”
a clock cycle of the sample clock, resynchronizing to
the reset phase. Note that the data stream in the auxiliary and primary ports has reversed. Before reset was
ADC SAMPLES ON THE RISING EDGE OF CLK+
n+3
n+4
n+5
n+6
n+7
n+8
n+9
n+10
n+11
n+12
n+13
tHD
RSTIN+
DREADYDREADY
DREADY+
AUXILIARY
DATA PORT
n-1
n+1
n+3
PRIMARY
DATA PORT
n
n+2
n+4
RESET OUT
DATA PORT
RSTOUTRSTOUT+
NOTE: THE LATENCY TO THE RESET OUTPUT IS 6.5 CLOCK CYCLES. THE LATENCY TO THE PRIMARY PORT IS 7.5 CLOCK CYCLES, AND
THE LATENCY TO THE AUXILIARY PORT IS 8.5 CLOCK CYCLES. ALL DATA PORTS ARE UPDATED ON THE RISING EDGE OF THE DREADY+ CLOCK.
Figure 18. Reset Output Timing in Demuxed DIV2 Mode (DREADY Aligned)
22
______________________________________________________________________________________
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
CLKCLK
CLK+
RESET
INPUT
n
n+1
n+2
tSU
RSTIN-
MAX104
ADC SAMPLE NUMBER
ADC SAMPLES ON THE RISING EDGE OF CLK+
n+3
n+4
n+5
n+6
n+7
n+8
n+9
n+10
n+11
n+12
n+13
tHD
RSTIN+
DREADY+
CLOCK PULSE “SWALLOWED”
DREADY
DREADY-
OUT-OF-SEQUENCE SAMPLE
AUXILIARY
DATA PORT
n-2
n
n+2
PRIMARY
DATA PORT
n-1
n+1
n+4
RESET OUT
DATA PORT
RSTOUTRSTOUT+
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.
Figure 19. Reset Output Timing in Demuxed DIV2 Mode (DREADY Realigned)
asserted, the auxiliary port contained “even” samples
while the primary port contained “odd” samples. After
the 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 auxiliary port, regardless of the DREADY phase.
These examples illustrate the combinations that result
with a reset input signal of two clock cycles. It is also
possible to reset the internal MAX104 demux successfully with a reset pulse of only one clock cycle, provided
that the setup-time and hold-time requirements are met
with respect to the sample clock. However, this is not
recommended when additional external demuxes are
used.
Note that many external demuxes require that their
reset signals be asserted while they are clocked, and
may require more than one clock cycle of reset. More
importantly, 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” 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 temperature, it is possible to determine the die temperature
of the MAX104 under normal operating conditions by
observing the currents ICONST and IPTAT, at contacts
ICONST and IPTAT. ICONST and IPTAT are two 100µA
(nominal) currents that are designed to be equal at
+27°C. These currents are derived from the MAX104’s
internal precision +2.5V bandgap reference. ICONST is
designed to be temperature independent, while IPTAT is
directly proportional to the absolute temperature. These
currents are derived from pnp current sources referenced from VCCI and driven into two series diodes connected to GNDI. The contacts ICONST and IPTAT may
be left open, because internal catch diodes prevent
saturation of the current sources. The simplest method
______________________________________________________________________________________
23
MAX104
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
of determining the die temperature is to measure each
current with an ammeter (which shuts off the internal
catch diodes) referenced to GNDI. The die temperature
in °C is then calculated by the expression:
 I

TDIE = 300 ⋅  PTAT  − 273
 ICONST 
Another method of determining the die temperature
uses the operational amplifier circuit shown in Figure 20.
The circuit produces a voltage that is proportional to
the die temperature. A possible application for this signal is speed control for a cooling fan, to maintain constant MAX104 die temperature. The circuit operates by
converting the ICONST and IPTAT currents to voltages
VCONST and VPTAT, with appropriate scaling to account
for their equal values at +27°C. This voltage difference
is then amplified by two amplifiers in an instrumentation-amplifier configuration with adjustable gain. The
nominal value of the circuit gain is 4.5092V/V. The gain
of the instrumentation amplifier is given by the expression:
VTEMP
AV =
VCONST − VPTAT
AV = 1 +
To calibrate the circuit, first connect pins 2-3 on JU1 to
zero the input of the PTAT path. With the MAX104 powered up, adjust potentiometer R3 until the voltage at the
VTEMP output is -2.728V. Connecting pins 1-2 on JU1
restores normal operation to the circuit after the calibration is complete. The voltage at the VTEMP node will
then be proportional to the actual MAX104 die temperature according to the equation:
TDIE (°C) = 100 · VTEMP
The overall accuracy of the die temperature measurement using the operational-amplifier scaling circuitry is
limited mainly by the accuracy and matching of the
resistors in the circuit.
Thermal Management
Depending on the application environment for the
ESBGA-packaged MAX104, the customer may have to
apply an external heatsink to the package after board
assembly. Existing open-tooled heatsinks are available
from standard heatsink suppliers (see Heatsink
Manufacturers). The heatsinks are available with preapplied adhesive for easy package mounting.
R1
R1
+ 2⋅
R2
R3
3.32k
6.65k
10-TURN
R2
15k
R1
7.5k
IPTAT
5k
R2
15k
JU1
1
12.1k
6.65k
2
3 VPTAT
1/4 MAX479
1/4 MAX479
R1
7.5k
12.1k
ICONST
VCONST
VTEMP
1/4 MAX479
1/4 MAX479
6.05k
Figure 20. Die Temperature Acquisition Circuit with the MAX479
24
______________________________________________________________________________________
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
THERMAL RESISTANCE vs. AIRFLOW
18
MAX104 θJA (°C/W)
WITHOUT
HEATSINK
WITH HEATSINK
0
16.5
12.5
200
14.3
9.4
400
13
8.3
800
12.5
7.4
16
WITHOUT
HEATSINK
14
Thermal Performance
The MAX104 has been modeled to determine the thermal resistance from junction to ambient. Table 7 lists
the ADC’s thermal performance parameters:
Ambient Temperature:
TA = +70°C
Heatsink Dimensions:
25mm x 25mm x 10mm
PC Board Size and Layout:
4" x 4"
2 Signal Layers
2 Power Layers
Heatsink Manufacturers
Aavid Engineering and IERC provide open-tool, lowprofile heatsinks, fitting the 25mm x 25mm ESBGA
package.
Aavid Engineering, Inc.
Phone: 714-556-2665
Heatsink Catalog #: 335224B00032
Heatsink Dimensions: 25mm x 25mm x 10mm
International Electronic Research Corporation (IERC)
Phone: 818-842-7277
Heatsink Catalog #: BDN09-3CB/A01
Heatsink Dimensions: 23.1mm x 23.1mm x 9mm
Bypassing/Layout/Power Supply
Grounding and power-supply decoupling strongly influence the MAX104’s performance. At 1GHz clock frequency and 8-bit resolution, unwanted digital crosstalk
may couple through the input, reference, power supply,
and ground connections and adversely influence the
dynamic performance of the ADC. Therefore, closely
follow the grounding and power-supply decoupling
guidelines (Figure 22).
θJA (°C/W)
AIRFLOW
(linear ft./min.)
MAX104
Table 7. Thermal Performance for
MAX104 With or Without Heatsink
12
10
WITH HEATSINK
8
6
0
100 200 300 400 500 600 700 800
AIRFLOW (linear ft./min.)
Figure 21. MAX104 Thermal Performance
Maxim strongly recommends using a multilayer printed
circuit board (PCB) with separate ground and powersupply planes. Since the MAX104 has separate analog
and digital ground connections (GNDA, GNDI, GNDR,
and GNDD, respectively), the PCB should feature separate analog and digital ground sections connected at
only one point (star ground at the power supply). Digital
signals should run above the digital ground plane, and
analog signals should run above the analog ground
plane. Keep digital signals far away from the sensitive
analog inputs, reference inputs, and clock inputs. Highspeed signals, including clocks, analog inputs, and
digital outputs, should be routed on 50Ω microstrip
lines, such as those employed on the MAX104EVKIT.
The MAX104 has separate analog and digital powersupply inputs: VEE (-5V analog and substrate supply)
and VCCI (+5V) to power the T/H amplifier, clock distribution, bandgap reference, and reference amplifier;
V CCA (+5V) to supply the ADC’s comparator array;
VCCO (+3V to VCCD) to establish power for all PECLbased circuit sections; and VCCD (+5V) to supply all
logic circuits of the data converter.
The MAX104 V EE supply contacts must not be left
open while the part is being powered up. To avoid this
condition, add a high-speed Schottky diode (such as a
Motorola 1N5817) between VEE and GNDI. This diode
prevents the device substrate from forward biasing,
which could cause latchup.
______________________________________________________________________________________
25
MAX104
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
All supplies should be decoupled with large tantalum or
electrolytic capacitors at the point where they enter the
PCB. For best performance, bypass all power supplies
to the appropriate ground with a 10µF tantalum capacitor, to filter power-supply noise, in parallel with a 0.01µF
capacitor and a high-quality 47pF ceramic chip capacitor located very close to the MAX104 device, to filter
very high-frequency noise.
line can be either a best-straight-line fit or a line drawn
between the endpoints of the transfer function, once
offset and gain errors have been nullified. The static linearity parameters for the MAX104 are measured using
the best-straight-line fit method.
Differential Nonlinearity (DNL)
Differential nonlinearity is the difference between an
actual step width and the ideal value of 1LSB. A DNL
error specification of less than 1LSB guarantees no
missing codes and a monotonic transfer function.
Static Parameter Definitions
Integral Nonlinearity (INL)
Integral nonlinearity is the deviation of the values on an
actual transfer function from a straight line. This straight
VCCO
GNDD
10µF
10nF
10nF
47pF
10µF
10nF
10nF
47pF
47pF
47pF
47pF
47pF
47pF
NOTE:
LOCATE ALL 47pF CAPACITORS AS CLOSE
AS POSSIBLE TO THE MAX104 DEVICE.
VCCI
GNDI
47pF
VEE
VCCA
10µF
1N5817
GNDI
GNDA
10µF
10nF
10nF
47pF
10nF
47pF
47pF
47pF
VCCA = +4.75V TO +5.25V
VCCD = +4.75V TO +5.25V
VCCI = +4.75V TO +5.25V
VCCO = +3.0V TO VCCD
VEE = -4.75V TO -5.25V
VCCD
GNDD
10nF
10µF
10nF
10nF
47pF
47pF
47pF
47pF
Figure 22. MAX104 Bypassing and Grounding
26
______________________________________________________________________________________
47pF
47pF
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
Effective Number of Bits (ENOB)
ENOB indicates the global accuracy of an ADC at a
specific input frequency and sampling rate. An ideal
ADC’s error consists of quantization noise only. ENOB
is calculated from a curve fit referenced to the theoretical full-scale range.
Dynamic Parameter Definitions
Total Harmonic Distortion (THD)
THD is the ratio of the RMS sum of the first five harmonics of the input signal to the fundamental itself. This is
expressed as:
Signal-to-Noise Ratio (SNR)
For a waveform perfectly reconstructed from digital
samples, the theoretical maximum SNR is the ratio of
the full-scale analog input (RMS value) to the RMS
quantization error (residual error). The ideal, theoretical
minimum analog-to-digital noise is caused by quantization error only and results directly from the ADC’s resolution (N bits):
SNR(MAX) = (6.02 · N + 1.76)dB
In reality, there are other noise sources besides quantization noise: thermal noise, reference noise, clock jitter,
etc. SNR is calculated by taking the ratio of the RMS
signal to the RMS noise, which includes all spectral
components minus the fundamental, the first five harmonics, and the DC offset.
Signal-to-Noise Plus Distortion (SINAD)
SINAD is calculated from the effective number of bits
(ENOB) as follows:
SINAD = (6.02 · ENOB) + 1.76


2
2
2
2
THD = 20 log   V2 + V3 + V4 + V5  / V1

 

⋅
where V1 is the fundamental amplitude, and V2 through
V5 are the amplitudes of the 2nd- through 5th-order
harmonics.
Spurious-Free Dynamic Range (SFDR)
SFDR is the ratio, expressed in decibels, of the RMS
amplitude of the fundamental (maximum signal component) to the RMS value of the next largest spurious
component, excluding DC offset.
Intermodulation Distortion (IMD)
The two-tone IMD is the ratio, expressed in decibels, of
either input tone to the worst 3rd-order (or higher) intermodulation products. The input tone levels are at -7dB
full scale.
Chip Information
TRANSISTOR COUNT: 20,486
SUBSTRATE CONNECTED TO VEE
______________________________________________________________________________________
27
MAX104
Bit Error Rates (BER)
Errors resulting from metastable states may occur when
the analog input voltage (at the time the sample is taken)
falls close to the decision point of any one of the input
comparators. Here, the magnitude of the error depends
on the location of the comparator in the comparator network. If it is the comparator for the MSB, the error will
reach full scale. The MAX104’s unique encoding scheme
solves this problem by limiting the magnitude of these
errors to 1LSB; it reduces the probability of these errors
occurring to typically one in every 1016 clock cycles.
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
MAX104
Typical Operating Circuit
Z0 = 50Ω
50Ω
+5V ANALOG
-5V ANALOG
+5V DIGITAL
VEE
VCCA
VCCI
+3.3V DIGITAL
VCCD AUXEN1 VCCO AUXEN2
DIVSELECT
+5V DIGITAL
ALL PECL OUTPUTS
MUST BE TERMINATED
VCCO - 2V
LIKE THIS.
OR+/OR-
DEMUXEN
2
2 P7+/P7-
VOSADJ
2
P6+/P62 P5+/P5-
Z0 = 50Ω
Z0 = 50Ω
VIN+
PRIMARY
PECL
OUTPUTS
VIN-
2
2 P3+/P32
SAMPLE
CLOCK
1GHz
+4dBm
MAX104
Z0 = 50Ω
P4+/P4-
P2+/P2-
2 P1+/P1-
CLK+
2
P0+/P02 A7+/A7-
CLK-
2
50Ω
A6+/A6-
2 A5+/A5-
GNDI
CLKCOM
AUXILARY
PECL
OUTPUTS
GNDI
2
A4+/A42 A3+/A32
A2+/A2-
2 A1+/A1RSTIN+
2
A0+/A0-
RSTINDREADY+/DREADYRSTOUT+/RSTOUTGNDA GNDR GNDI
28
2
2
GNDD REFOUT REFIN
______________________________________________________________________________________
TO MEMORY OR DIGITAL SIGNAL PROCESSOR
DIFFERENTIAL
ANALOG
INPUT
500mVp-p FS
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
TOP VIEW
MAX104
______________________________________________________________________________________
29
MAX104
192-Contact ESBGA PCB Land Pattern
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
SUPER BGA.EPS
MAX104
Package Information
30
______________________________________________________________________________________
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
______________________________________________________________________________________
31
MAX104
Package Information (continued)
MAX104
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
NOTES
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
32 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
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