Bias Generator. LM7705 Datasheet

LM7705 Generator. Datasheet pdf. Equivalent

LM7705 Datasheet
Recommendation LM7705 Datasheet
Part LM7705
Description Low-Noise Negative Bias Generator
Feature LM7705; Product Folder Order Now Technical Documents Tools & Software Support & Community LM7705 SNVS42.
Manufacture etcTI
Datasheet
Download LM7705 Datasheet




etcTI LM7705
Product
Folder
Order
Now
Technical
Documents
Tools &
Software
Support &
Community
LM7705
SNVS420D – NOVEMBER 2008 – REVISED MAY 2018
LM7705 Low-Noise Negative Bias Generator
1 Features
1 Regulated Output Voltage 0.232 V
• Output Voltage Tolerance 5%
• Output Voltage Ripple 4 mVPP
• Supply Voltage 3 V to 5.25 V
• Conversion Efficiency Up to 98%
• Quiescent Current 78 µA
• Shutdown Current 20 nA
• Turnon Time 500 µs
• Operating Temperature Range 40°C to 125°C
• 8-Pin VSSOP Package
2 Applications
• True Zero Amplifier Outputs
• Portable Instrumentation
• Low-Voltage Split-Power Supplies
3 Description
The LM7705 device is a switched capacitor voltage
inverter with a low noise, 0.23 V fixed negative
voltage regulator. This device is designed to be used
with low voltage amplifiers to enable the amplifiers
output to swing to zero volts. The 0.23 V is used to
supply the negative supply pin of an amplifier while
maintaining less then 5.5 V across the amplifier. Rail-
to-Rail output amplifiers cannot output zero volts
when operating from a single-supply voltage and can
result in error accumulation due to amplifier output
saturation voltage being amplified by following gain
stages. A small negative supply voltage will prevent
the amplifiers output from saturating at zero volts and
will help maintain an accurate zero through a signal
processing chain. Additionally, when an amplifier is
used to drive an input of the ADC, the amplifier can
output a zero voltage signal and the full input range
of an ADC can be used. The LM7705 device has a
shutdown pin to minimize standby power
consumption.
Device Information(1)
PART NUMBER
PACKAGE
BODY SIZE (NOM)
LM7705
VSSOP (8)
3.00 mm × 3.00 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Typical Application
+V low voltage
amplifier
+V
+ In +
CFLY
- In -
-V
true zero
output voltage
shutdown
CRES
CF+ CF-
VDD
SD VOUT
LM7705
CRES
VSS
VSS
-0.23V
COUT
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.



etcTI LM7705
LM7705
SNVS420D – NOVEMBER 2008 – REVISED MAY 2018
www.ti.com
Table of Contents
1 Features .................................................................. 1
2 Applications ........................................................... 1
3 Description ............................................................. 1
4 Revision History..................................................... 2
5 Pin Configuration and Functions ......................... 3
6 Specifications......................................................... 3
6.1 Absolute Maximum Ratings ...................................... 3
6.2 ESD Ratings.............................................................. 3
6.3 Recommended Operating Conditions....................... 4
6.4 Thermal Information .................................................. 4
6.5 3.3-V Electrical Characteristics ................................. 4
6.6 5-V Electrical Characteristics .................................... 5
6.7 Typical Characteristics .............................................. 6
7 Detailed Description ............................................ 10
7.1 Overview ................................................................. 10
7.2 Functional Block Diagram ....................................... 10
7.3 Feature Description................................................. 10
7.4 Device Functional Modes........................................ 10
8 Application and Implementation ........................ 14
8.1 Application Information............................................ 14
8.2 Typical Application .................................................. 16
9 Power Supply Recommendations...................... 18
10 Layout................................................................... 19
10.1 Layout Guidelines ................................................. 19
10.2 Layout Examples................................................... 19
11 Device and Documentation Support ................. 20
11.1 Community Resources.......................................... 20
11.2 Trademarks ........................................................... 20
11.3 Electrostatic Discharge Caution ............................ 20
11.4 Glossary ................................................................ 20
12 Mechanical, Packaging, and Orderable
Information ........................................................... 20
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision C (September 2015) to Revision D
Page
• Deleted 'Maximum Output Current 26 mA' from Features list ............................................................................................... 1
• Deleted IO_MAX spec from 3.3-V Electrical Characteristics and 5-V Electrical Characteristics tables.................................. 4
Changes from Revision B (March 2013) to Revision C
Page
• Added Pin Configuration and Functions section, ESD Ratings table, Feature Description section, Device Functional
Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device
and Documentation Support section, and Mechanical, Packaging, and Orderable Information section .............................. 1
Changes from Revision A (November 2008) to Revision B
Page
• Changed layout of National Semiconductor Data Sheet to TI format .................................................................................. 19
2 Submit Documentation Feedback
Product Folder Links: LM7705
Copyright © 2008–2018, Texas Instruments Incorporated



etcTI LM7705
www.ti.com
5 Pin Configuration and Functions
LM7705
SNVS420D – NOVEMBER 2008 – REVISED MAY 2018
DGK Package
8-Pin VSSOP
Top View
18
LM7705
45
NAME
CF+
VSS
SD
VDD
VSS
VOUT
CRES
CF-
PIN
NO.
1
2
3
4
5
6
7
8
Pin Functions
TYPE
DESCRIPTION
Analog
Ground
Input
Power
Ground
Output
Analog
Analog
CFLY Positive Capacitor Connection
Power Ground
Shutdown Pin
If SD pin is LOW, device is ON
If SD pin is HIGH, device is OFF
Positive Supply Voltage
Power Ground
Output Voltage
Reserve Capacitor Connection
CFLY Negative Capacitor Connection
6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1)
Supply voltage VDD - VSS
SD
Junction temperature(2)
Mounting temperature
Storage temperature, Tstg
Infrared or Convection (20 sec)
MIN
VDD + 0.3
65
MAX
5.75
VSS – 0.3
150
260
150
UNIT
V
V
°C
°C
°C
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) Typical values represent the most likely parametric norm as determined at the time of characterization. Actual typical values may vary
over time and will also depend on the application and configuration. The typical values are not tested and are not ensured on shipped
production material.
6.2 ESD Ratings
V(ESD) Electrostatic discharge
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001(1)
Charged-device model (CDM), per JEDEC specification JESD22-
C101 (2)
Machine model(3)
(1) Human Body Model, applicable std. MIL-STD-883, Method 3015.7.
(2) Field induced Charge-Device Model, applicable std. JESD22–C101–C. (ESD FICDM std of JEDEC).
(3) Machine model, applicable std JESD22–A115–A (ESSD MM srd of JEDEC).
VALUE
±2000
±750
±200
UNIT
V
Copyright © 2008–2018, Texas Instruments Incorporated
Product Folder Links: LM7705
Submit Documentation Feedback
3







@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site (Privacy Policy & Contact)