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

ASNT6123-BD
25Gbps Dual TIA
Broadband dual transimpedance amplifier (TIA) for low noise receiver-side applications

Two independent amplification channels

Automatic DC offset adjustment

Input peak detectorsManual bandwidth/peaking adjustment



Independent common-mode voltage adjustment for each single-ended output

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

Fully differential input and output buffers with on-chip 50Ohm termination

Single +3.3V or -3.3V power supply

Low current consumption of 150mA at nominal conditions



Fabricated in SiGe for high performance, yield, and reliability

2640
39 38 37 36 35 34 33 32 31 30 29 28 27

12345ASNT6123

7 89 10 11 12 13 14 15 16 17 18 19206Rev. 2.3.2

25242322211May 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.comDESCRIPTION

pkdet1PDChannel 1

BWcrl
inp1
inn1

LATIA

cfilt1

OAOSC
pkdet2PDChannel 2

BWcrl
inp2
inn2
cfilt2peakadj1
dcoutp1
outp1
outn1
dcoutn1

TIALAOA

peakadj2
dcoutp2
outp2
outn2
dcoutn2

OSC
Fig. 1. Functional Block Diagram

The ASNT6123-BD SiGe IC is a two-channel temperature stable SiGe transimpedance amplifier thatprovides low-jitter broadband linear conversion of current signals at its input ports (inp1/inn1, inp2/inn2)
into differential voltage signals at the output ports (outp1/outn1, outp2/outn2). Each channel of the partshown in Fig. 1 is a serial combination of transimpedance (TIA), limiting (LA), and output (OA)
amplification stages. The input signal can be either differential or single-ended with the current always
flowing into the corresponding pin. In case of one input being single-ended, a certain DC level signal
must be applied to the other input. The part incorporates an automatic DC offset control (OSC) that
effectively eliminates any difference between the common-mode voltages of direct and inverted output
signals. This function requires utilization of external capacitors attached to cfilt1 and cfilt2 pads.
The DC common-mode voltage level of each single-ended output can be manually adjusted using thecorresponding dcoutp1/dcoutn1 or dcoutp2/dcoutn2 control inputs.
The individual amplifier bandwidth can be manually adjusted through changing its peaking characteristics
by means of peakadj1 or peakadj2 control signals.
Rev. 2.3.2

2May 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

The on-chip peak detectors (PD) provide output signals pkdet1 and pkdet2 that are proportional to thevalues of the corresponding input signals.
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, which may be also kept separate
from the intermediate amplifier supply vccl. The input and output negative supply nets are also created as
separate metal plains veea and veed, which are partly shorted through the common substrate.

POWER SUPPLY CONFIGURATION
The part can operate with either negative supply (vcca=vccl=vccd=0.0V=ground and veea=veed=−3.3V), or positive supply (vcca=vccl=vccd=+3.3V and veea=veed=0.0V=ground). In case of thepositive supply, all outputs need AC termination when connected to any devices with 50Ohm termination
to ground.
The chip substrate should be completely isolated or connected to veea or veed. DO NOT connect
substrate to vcca, vccl, or vccd!

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

Rev. 2.3.2

Min-4010103Max
3.6
0.6
2+125+100
9898

Units
VWmAºCºC%%

May 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

TERMINAL FUNCTIONSTERMINAL
NameNo.
Type
inp1
inn1
inp2
inn2
outp1
outn1
outp2
outn2
dcoutp1
dcoutn1dcoutp2dcoutn2
pkadj1
pkadj2
pkdet1
pkdet2
cfilt1
cfilt2
Name
vcca
vccl
vccd
veea
veed

Rev. 2.3.2

DESCRIPTION

High-Speed I/Os
29
Current Direct and inverting single-ended current-sensing data inputs
input for channel 1
31
35
Direct and inverting single-ended current-sensing data inputs
for channel 237
17
CML Differential data outputs for channel 1. Require external SE
output 50Ohm termination to vccd
1511
Differential data outputs for channel 2. Require external SE50Ohm termination to vccd
9Controls
27
Control DC common-mode voltage control with 1KOhm to outp1
voltage DC common-mode voltage control with 1KOhm to outn1
1939
DC common-mode voltage control with 1KOhm to outp2
7
DC common-mode voltage control with 1KOhm to outn2
22Channel 1 peaking control signal
4Channel 2 peaking control signal
23
Analog Channel 1 peak detector output
signal Channel 2 peak detector output
324300nF off-chip capacitor connection for channel 1
2300nF off-chip capacitor connection for channel 2
Supply and Termination Voltages
Description
Pin Number
Positive power supply for TIAs (+3.3V or 0V)
40, 26, 33
Positive power supply for internal cells (+3.3V or 0V)
1, 5, 21, 25
Positive power supply for output buffers (+3.3V or 0V)6, 13, 20
Negative power supply for TIAs (0V or -3.3V)
28, 30, 32, 34, 36, 38
Negative power supply for other cells (0V or -3.3V)8, 10, 12, 14, 16, 18

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

ELECTRICAL CHARACTERISTICSPARAMETER

MIN

TYP

MAX UNITCOMMENTS
General Parameters
3.1
3.3
3.5
V
±6%
vcca
3.1
3.3
3.5
V
±6%
vccd
3.1
3.3
3.5
V
±6%
vccl
0.0
V
External ground
veea
0.0
V
External groundveedIvee
150mATotal current from negative supplies
Power consumption
495mW
Junction temperature -25
50125°C
HS Input Data (inp1/inn1, inp2/inn2)
Data Rate
DC25Gbps
Bandwidth1620
GHz-3dB level
SE Current Swing
1500uA
Positive (into the pin)
OSC frequency
10KHz
With 300nF external capacitor
Input Control Voltages (pkadj1, pkadj2, dcoutp1/dcoutn1, dcoutp2/dcoutn2)
Frequency
DC
Logic “0” level
Vvee
Logic “1” level
Vvcc
HS Output Data (outp1/outn1, outp2/outn2)
Data rate
DC25Gbps
Differential gain
77
81dBOhm
Single-ended swing
0.270.32
V
Peak-to-peak
CM Levelvcc-(Swing)/2V
With external 50Ohm DC termination
Input-referred noise
1525
pA/Hz1/2
0.1GHz-20GHz
Additive Jitter2ps
Peak-to-peak

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 2400µm
The part’s die incorporates wire bonding pads with the coordinates of their centers given in This device
complies with the Restriction of Hazardous Substances (RoHS) per 2011/65/EU for all ten substances.
Table 3.

Rev. 2.3.25May 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

The part’s identification label is ASNT6123-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.
Table 3. Die Pad Coordinates

Pin
Number
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39

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

Y Coordinate,
µm
58
58
58
300
600
900
1200
1500
1800
2100
2342
2342
2342
2100
1800
1500
1200
900
600
300

Pin
Number
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40

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

Y Coordinate,
µm
58
58
135
450
750
1050
1350
1650
1950
2265
2342
2342
2265
19501650
1350
1050
750450135

REVISION HISTORY
Revision
2.3.2
2.2.2
2.2.1

Date
05-2020
07-2019
04-2017

2.1.1
2.0.1

03-2015
12-2013

Rev. 2.3.2

Changes
Updated Die Information
Updated Letterhead
Added description of substrate connection
Updated absolute maximum ratings section
Corrected electrical characteristics section
Added gain value
Corrected description
Corrected format
Added die drawing
Corrected block diagram
Added power supply configuration section
Added absolute maximum ratings section
Corrected electrical characteristics
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

1

Rev. 2.3.2

01-2010Added die information
Added revision history tableFirst release

7May 2020