adl5304 Analog Devices, Inc., adl5304 Datasheet - Page 6

• Manufacturer Part Number: adl5304
• Description: High Speed, 200 Db Range, Logarithmic Converter
• Manufacturer: Analog Devices, Inc.

ADL5304
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Table 3. Pin Function Descriptions
Pin No.
1, 25
2, 3, 7, 8
4
5
6
9
10
11
12
13
14
15, 18
16
17
19
20
21
22
23
24
26
27
28
29
30
31
32
EPAD
Mnemonic
NC
VSM1 to VSM4
INUM
IDEN
IREF
VDEN
INDN
COMM
NMFS
VNEG
DNFS
ACOM
HFCP
2VLT
SCL3
SCL2
SCL1
VLOG
INMS
INPS
1P5V
DCBI
BSDC
VPOS
IMON
INNM
VNUM
PAD
Denominator Current Input. Connect to the IREF pin for most applications.
Denominator Voltage Input to Temperature Compensation Circuit.
Description
No Connect. Do not connect to these pins.
Guard Pins for the INUM and IDEN Inputs. Connect these pins to the 1P5V, DCBI, and INPS pins for default
single-supply setup; connect to ground if INUM (photodiode bias) is desired to be at ground (must have −5 V
< VNEG < −2 V).
Numerator Current Input.
100 nA Trimmed Reference Current Output. Connect to the IDEN pin for most applications.
Voltage Output of Denominator Log Amplifier. Connect this pin to the INDN pin and decouple with an
external 0.1 μF capacitor to ground.
Main Ground.
Numerator Speed Bias (Nominal 1 kΩ Resistor to VNEG Pin).
Negative Supply.
Denominator Speed Bias (Nominal 1 kΩ Resistor to VNEG Pin).
Analog Common, Low Noise Reference Ground. Important that both pins are always grounded.
High Frequency Compensation.
2.0 V Reference Output.
7.5 kΩ Scaling Resistor (See Figure 1). Default is NC.
5 kΩ Scaling Resistor (See Figure 1). Default is to connect to the INMS pin.
5 kΩ Scaling Resistor (See Figure 1). Default is to connect to the VLOG pin.
Primary Logarithmic Output. For I
Output Buffer Amplifier Inverting Input.
Output Buffer Amplifier Noninverting Input. The INPS, DCBI, and VSM1 to VSM4 pins must be tied together.
1.5 V Reference Output. Connect to the INPS, DCBI, and VSM1 to VSM4 pins for single-supply operation.
~1.3 mA Bias Current. Connect this pin to the VSM1 to VSM4 pins. See Pin 2, Pin 3, Pin 7, and Pin 8 description.
Internal Bias Node. Decouple with a series connection of 4 Ω and 1 μF to ground.
Positive Supply.
Photodiode Monitor Output. I
Numerator Voltage Input to Temperature Compensation Circuit.
Voltage Output of Numerator Log Amplifier. Connect this pin to the INNM pin. For the fastest response, do
not add an external capacitor.
Exposed paddle. Connect the exposed paddle to the VSM1 to VSM4 pins to provide low leakage guard.
NOTES
1. NC = NO CONNECT. DO NOT CONNECT TO THIS PIN.
2. CONNECT EXPOSED PADDLE TO VSM1 THROUGH
VSM4 PINS TO PROVIDE LOW LEAKAGE GUARD.
VSM1
VSM2
VSM3
VSM4
INUM
IDEN
IREF
Figure 2. 32-Lead LFCSP Pin Configuration
NC
1
2
3
4
5
6
7
8
MON
Rev. 0 | Page 6 of 32
(Not to Scale)
ADL5304
PIN 1
INDICATOR
TOP VIEW
NUM
= 1.1 × I
= I
DEN
NUM
, the VLOG pin is at the voltage applied to the INPS pin.
.
24 INPS
23 INMS
22 VLOG
21 SCL1
20 SCL2
19 SCL3
18 ACOM
17 2VLT
Data Sheet