Advanced Science And Novel Technology Company, Inc.
2790 Skypark Drive Suite 112, Torrance, CA 90505
Offices: 310-530-9400 / Fax: 310-530-9402
www.adsantec.com

ASNT6121-BD
45Gbps Linear/Limiting TIA
Broadband transimpedance amplifier (TIA) for low noise receiver-side applications



Manual bandwidth/peaking control



Automatic DC offset adjustment

Input peak detector

On-chip temperature detector



Exhibits low jitter and limited temperature variation over industrial temperature range

Fully differential output buffer with on-chip 50Ohm termination

Single +3.3V or -3.3V power supply

Low current consumption of 145mA at nominal conditions

Fabricated in SiGe for high performance, yield, and reliability

1319ASNT6121

71Rev. 2.3.2

1May 2020

Advanced Science And Novel Technology Company, Inc.
2790 Skypark Drive Suite 112, Torrance, CA 90505
Offices: 310-530-9400 / Fax: 310-530-9402
www.adsantec.com

DESCRIPTION
pkdet

PkD
BWcrl
inp
inncfilt

TIA

LAOA

pkadj
dcoutpoutp
outn
dcoutnOSC
Fig. 1. Functional Block Diagram

The ASNT6121-BD IC is a temperature stable SiGe transimpedance amplifier that provides low-jitter
broadband conversion of current signals at its input port inp into differential voltage signals at the output
ports outp/outn. The part shown in Fig. 1 is a serial combination of transimpedance (TIA), limiting (LA),and linearized output (OA) amplification stages. The part operates as a linear amplifier for low input
currents and moves to limiting mode above the specified maximum Non-Limiting Current Swing (seeELECTRICAL CHARACTERISTICS). The input signal should be single-ended with the current flowing
into the inp pin. It is recommended to decouple the inn pin to ground with a 10nF capacitor. The part
incorporates a control block (BWcrl) with an external port pkadj for adjustment of the total bandwidth or
peaking of the amplifier, as well as an automatic DC offset control (OSC) that effectively eliminates any
difference between the common-mode voltages of direct and inverted output signals. The offset
compensation function requires utilization of an external 100nF capacitor attached to the cfilt pad. The
output common mode voltages on output pins outp/outn can be adjusted using analog ports
dcoutp/dcoutn respectively.
The on-chip peak detector (PkD) provides an output signal pkdet proportional to the value of the input
signal.
The on-chip temperature sensor is a diode with its anode connected to the dtemp port.
The part’s outputs support a CML-type interface with on-chip 50Ohm termination and may be used as adifferential or single-ended connection with AC or DC-coupling (see also POWER SUPPLYCONFIGURATION). The input and output termination resistors in both channels are respectively
connected to separate internal positive supply plains vcca and vccd. The input and output negative
supply nets are also created as separate metal plains veea and veed, which are partly shorted through thecommon substrate.

POWER SUPPLY CONFIGURATION
The part can operate with either negative supply (vcc = 0.0V = ground and vee = −3.3V), or positive
supply (vcc = +3.3V and vee = 0.0V = ground). In case of the positive supply, all I/Os need AC
termination when connected to any devices with 50Ohm termination to ground.
The chip substrate should be connected to vee or completely isolated. DO NOT connect substrate to vcc!
Rev. 2.3.2May 20202

Advanced Science And Novel Technology Company, Inc.
2790 Skypark Drive Suite 112, Torrance, CA 90505
Offices: 310-530-9400 / Fax: 310-530-9402
www.adsantec.com

All the characteristics detailed below assume vcc = 3.3V and vee = 0.0V.

ABSOLUTE MAXIMUM RATINGS
Caution: Exceeding the absolute maximum ratings shown in Table 1 may cause damage to this productand/or lead to reduced reliability. Functional performance is specified over the recommended operating
conditions for power supply and temperature only. AC and DC device characteristics at or beyond theabsolute maximum ratings are not assumed or implied. All min and max voltage limits are referenced toground (assumed vee).
Table 1. Absolute Maximum Ratings

Parameter
Supply Voltage (vcc)
Power Consumption
RF Input Current Swing (SE)
Junction Temperature
Storage Temperature
Operational Humidity
Storage Humidity

Min-40
1010

Max
3.6
0.56
4+125
+1009898UnitsVWmAºCºC%%TERMINAL FUNCTIONSTERMINAL
NameNo.
Typeinpinnoutp
outn
dcoutpdcoutn
pkadj
pkdet
cfilt
dtemp
Namevccdvcca
veedveea

Rev. 2.3.2

DESCRIPTION

High-Speed I/Os
20
Current Single-ended current-sensing data input
input Additional input. 10nF decoupling to ground is recommended
22
10
CML Differential data outputs. Require external SE 50Ohm
output termination to vcc
8Controls
14
Input Analog control ports with internal 1K terminations tocorresponding data outputs outp/outn
43
Input Analog voltage port with internal 2.0KOhm termination to vcc
15Output Analog voltage port with internal 2.8KOhm termination to vcc
2100nF off-chip capacitor connection
16Output Temperature sensor output (sink current)
Supply and Termination Voltages
Description
Pin Number
Positive power supply (+3.3V or 0V)6, 12
Quiet positive power supply for TIA (+3.3V or 0V)
18, 24
Negative power supply (0V or -3.3V)
5, 7, 9, 11, 13
Quiet negative power supply for TIA (0V or -3.3V)
1, 17, 19, 21, 23

3May 2020

Advanced Science And Novel Technology Company, Inc.
2790 Skypark Drive Suite 112, Torrance, CA 90505
Offices: 310-530-9400 / Fax: 310-530-9402
www.adsantec.com

ELECTRICAL CHARACTERISTICSPARAMETERTYP MAX UNIT
COMMENTS
General Parameters
3.1
3.3
3.5
V
±6%
vccd
3.1
3.3
3.5
V
±6%
vcca
0.0
V
External ground
veed
0.0
V
External ground
veea
Ivee
145mA
Power consumption
480mW
Junction temperature
-2550
125°C
HS Input Data (inp/inn)
Data Rate
45GbpsBandwidth162023GHz-3dB level
Low Cutoff
2.2
4.4
KHz
-3dB level
Non-Limiting Current Swing
250uA
pk-pk, positive (into the pin)
Input Overload Current
2.0mA
CM Voltage Level
9901100mV
Defined by OSC
Output Common Mode Controls (dcoutp, dcoutn)
Voltage range
VFor linear DC offset controlveevcc
Bandwidth Control (pkadj)
Voltage range
vcc-1.0
vcc
V
Bandwidth0100
MHz
HS Output Data (outp/outn)
Data Rate
50GbpsTransimpedance
3.55.0KOhm
Non-saturated output
SE Swing
0.3
V
Peak-to-peak, saturated
CM Levelvcc-(Swing)/2V
External 50Ohm DC termination
Group Delay Variation±5ps
100MHz - 23GHz
1/2Input Referred Noise Density
23pA/Hz0 - 23GHz
Additive Jitter
1ps
Peak-to-peak, PRBS7 input
Peak Detector (pkdet)
Output Voltage range
vcc-1.0vcc
VFor input current of 80-2000μA

Rev. 2.3.2

MIN

4May 2020

Advanced Science And Novel Technology Company, Inc.
2790 Skypark Drive Suite 112, Torrance, CA 90505
Offices: 310-530-9400 / Fax: 310-530-9402
www.adsantec.com

SIMULATED CHARACTERISTICS

Fig. 2. Typical Output Eye at 200uA Input Current Swing and 45Gbps Data Rate

Fig. 3. Typical Output Eye at 200uA Input Current Swing and 50Gbps Data Rate

Rev. 2.3.2

5May 2020

Advanced Science And Novel Technology Company, Inc.
2790 Skypark Drive Suite 112, Torrance, CA 90505
Offices: 310-530-9400 / Fax: 310-530-9402
www.adsantec.com

Fig. 4. Typical S21 Characteristic

Fig. 5. Typical Group Delay

Rev. 2.3.2

6May 2020

Advanced Science And Novel Technology Company, Inc.
2790 Skypark Drive Suite 112, Torrance, CA 90505
Offices: 310-530-9400 / Fax: 310-530-9402
www.adsantec.com

DIE INFORMATION
The main dimensions of the die are given in Table 2.
Table 2. Important Die Dimensions

Pad metal dimensions
80µm x 80µm
Pad opening dimensions
74µm x74µm
Die dimensions
1200µm x 1200µm
The part’s die incorporates wire bonding pads with the coordinates of their centers given in Table 3.

Table 3. Die Pad Coordinates

Pin
Number
13
5
7
911
13
15
1719
21
23

X Coordinate,
µm
300
600
900
1142
1142
1142
900
600
300
58
58
58

Y Coordinate,
µm
58
58
58
300
600
900
1142
1142
1142
900
600
300

Pin
Number
2
4
6
8
10
12
14
16
18
20
2224

X Coordinate,
µm
450
750
1065
1142
1142
1065
750
450
135
58
58
135

Y Coordinate,
µm
58
58
135
450
750
1065
1142
1142
1065
750
450135The part’s identification label is ASNT6121-BD. The first 8 characters of the name before the dashidentify the bare die including general circuit family, fabrication technology, specific circuit type, and partversion while the 2 characters after the dash indicate that the die is not packaged.
This device complies with the Restriction of Hazardous Substances (RoHS) per 2011/65/EU for all ten
substances.

Rev. 2.3.2

7May 2020

Advanced Science And Novel Technology Company, Inc.
2790 Skypark Drive Suite 112, Torrance, CA 90505
Offices: 310-530-9400 / Fax: 310-530-9402
www.adsantec.comREVISION HISTORY
Revision
2.3.2
2.2.2
2.2.1

Date05-2020
07-2019
05-2017

2.1.1

04-2017

2.0.1

02-2017102-2010

Rev. 2.3.2

Changes
Updated Die Information
Updated Letterhead
Modified title
Corrected description of liner/limiting operational modes
Added description of substrate connection
Corrected Electrical Characteristics section
Fully revised description
Added power supply configuration
Added absolute maximum ratings
Added simulated characteristics
Added die information
Updated format
Preliminary release

8May 2020