Datasheet

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LT1638/LT1639

16389fg

TYPICAL APPLICATION

DESCRIPTION

1.2MHz, 0.4V/µs

Over-The-Top Micropower

Rail-to-Rail Input and Output

Op Amps

The LT

1638 is a low p wer dual rail-to-rail input and output

operational ampliﬁ er available in the standard 8-pin PDIP

and SO packages as well as the 8-lead MSOP package. The

LT1639 is a low power quad rail-to-rail input and output

operational ampliﬁ er offered in the standard 14-pin PDIP

and surface mount packages. For space limited applications

the LT1638 is available in a 3mm x 3mm x 0.8mm dual

ﬁ ne pitch leadless package (DFN).

The LT1638/LT1639 op amps operate on all single and split

supplies with a total voltage of 2.5V to 44V drawing only

170μA of quiescent current per ampliﬁ er. These ampli-

ﬁ ers are reverse battery protected and draw no current

for reverse supply up to 18V.

The input range of the LT1638/LT1639 includes both sup-

plies, and a unique feature of this device is its capability

to operate over the top with either or both of its inputs

above V

. The inputs handle 44V, both differential and

common mode, independent of supply voltage. The input

stage incorporates phase reversal protection to prevent

false outputs from occurring when the inputs are below

the negative supply. Protective resistors are included in

the input leads so that current does not become excessive

when the inputs are forced below the negative supply.

The LT1638/LT1639 can drive loads up to 25mA and still

maintain rail-to-rail capability. The op amps are unity-gain

stable and drive all capacitive loads up to 1000pF when

optional output compensation is used.

FEATURES

APPLICATIONS

Operates with Inputs Above V

Rail-to-Rail Input and Output

Low Power: 230μA per Ampliﬁ er Max

Gain Bandwidth Product: 1.2MHz

Slew Rate: 0.4V/μs

High Output Current: 25mA Min

Speciﬁ ed on 3V, 5V and ±15V Supplies

Reverse Battery Protection to 18V

No Supply Sequencing Problems

High Voltage Gain: 1500V/mV

Single Supply Input Range: –0.4V to 44V

High CMRR: 98dB

No Phase Reversal

Available in 14-Lead SO, 8-Lead MSOP and DFN

Packages

Battery- or Solar-Powered Systems

Portable Instrumentation

Sensor Conditioning

Supply Current Sensing

Battery Monitoring

Micropower Active Filters

4mA to 20mA Transmitters

–

1/2 LT1638

–

1/2 LT1638

10k

= 5V, V

= 0V TO 44V, t

= 27μs

1638/39 TA01

Over-The-Top

Comparator with

100mV Hysteresis Centered at 0mV

Output Voltage vs Input Voltage

1638/39 TA02

20mV/DIV

L, LT, LTC, LTM, Over-The-Top, Linear Technology and the Linear logo are registered

trademarks of Linear Technology Corporation. All other trademarks are the property of their

respective owners.

Summary of content (18 pages)

PAGE 1
LT1638/LT1639 1.2MHz, 0.4V/µs Over-The-Top Micropower Rail-to-Rail Input and Output Op Amps DESCRIPTION FEATURES n n n n n n n n n n n n n n Operates with Inputs Above V + Rail-to-Rail Input and Output Low Power: 230μA per Ampliﬁer Max Gain Bandwidth Product: 1.2MHz Slew Rate: 0.4V/μs High Output Current: 25mA Min Speciﬁed on 3V, 5V and ±15V Supplies Reverse Battery Protection to 18V No Supply Sequencing Problems High Voltage Gain: 1500V/mV Single Supply Input Range: –0.
PAGE 2
LT1638/LT1639 ABSOLUTE MAXIMUM RATINGS (Note 1) Total Supply Voltage (V + to V –) ................................44V Input Differential Voltage...........................................44V Input Current........................................................±25mA Output Short-Circuit Duration (Note 2) .........Continuous Operating Temperature Range (Note 3) LT1638C/LT1639C ................................–40°C to 85°C LT1638I/LT1639I ..................................–40°C to 85°C LT1638H/LT1639H ........
PAGE 3
LT1638/LT1639 ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LT1638CMS8#PBF LT1638CMS8#TRPBF LTCY 8-Lead Plastic MSOP –40°C to 85°C LT1638IMS8#PBF LT1638IMS8#TRPBF LTCY 8-Lead Plastic MSOP –40°C to 85°C LT1638CDD#PBF LT1638CDD#TRPBF LAAL 8-Lead (3mm × 3mm) Plastic DFN –40°C to 85°C LT1638IDD#PBF LT1638IDD#TRPBF LAAL 8-Lead (3mm × 3mm) Plastic DFN –40°C to 85°C LT1638CN8#PBF LT1638CN8#TRPBF LT1638CN8 8-Lead PDIP –40°
PAGE 4
LT1638/LT1639 ELECTRICAL CHARACTERISTICS The l denotes the speciﬁcations which apply over the speciﬁed temperature range, otherwise speciﬁcations are at TA = 25°C. VS = 3V, 0V; VS = 5V, 0V; VCM = VOUT = half supply, unless otherwise noted.
PAGE 5
LT1638/LT1639 ELECTRICAL CHARACTERISTICS The l denotes the speciﬁcations which apply over the speciﬁed temperature range, otherwise speciﬁcations are at TA = 25°C. VS = 3V, 0V; VS = 5V, 0V; VCM = VOUT = half supply, unless otherwise noted. (Note 4) LT1638C/LT1639C, LT1638I/LT1639I MIN TYP MAX SYMBOL PARAMETER CONDITIONS PSRR Power Supply Rejection Ratio VS = 3V to 12.
PAGE 6
LT1638/LT1639 ELECTRICAL CHARACTERISTICS The l denotes the speciﬁcations which apply over the speciﬁed temperature range, otherwise speciﬁcations are at TA = 25°C. VS = ±15V, VCM = OV, VOUT = OV, unless otherwise noted. (Note 4) LT1638C/LT1639C, LT1638I/LT1639I MIN TYP MAX SYMBOL PARAMETER CONDITIONS ISC Short-Circuit Current (Note 2) Short to GND 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C UNITS PSRR Power Supply Rejection Ratio VS = ± 1.
PAGE 7
LT1638/LT1639 ELECTRICAL CHARACTERISTICS The l denotes the speciﬁcations which apply over the full operating temperature range of – 40°C ≤ TA ≤ 125°C, otherwise speciﬁcations are at TA = 25°C. VS = ±15V, VCM = 0V, VOUT = 0V, VSHDN = V – unless otherwise speciﬁed. (Note 4) SYMBOL PARAMETER CONDITIONS VOS Input Offset Voltage LT1638S8 LT1639S MIN l l LT1638H/LT1639H TYP MAX UNITS 250 850 3.4 μV mV 350 950 3.
PAGE 8
LT1638/LT1639 TYPICAL PERFORMANCE CHARACTERISTICS Supply Current vs Supply Voltage 280 TA = 125°C 240 220 TA = 25°C 200 180 TA = –55°C 160 140 120 10000 300 8000 200 6000 100 0 TA = 125°C 5 10 15 20 25 30 35 SUPPLY VOLTAGE (V) 40 TA = –55°C –200 –300 –400 0 TA = 25°C –100 45 0 1 3 4 2 TOTAL SUPPLY VOLTAGE (V) Output Saturation Voltage vs Load Current (Output High) OUTPUT SATURATION VOLTAGE (V) OUTPUT SATURATION VOLTAGE (V) TA = 125°C TA = 25°C TA = –55°C 0.01 0.
PAGE 9
LT1638/LT1639 TYPICAL PERFORMANCE CHARACTERISTICS Gain and Phase Shift vs Frequency Gain Bandwidth Product vs Temperature 80 50 70 40 60 50 GAIN 20 40 10 30 0 20 1200 1100 1000 10 –10 10 100 FREQUENCY (kHz) 1 –25 50 0 75 25 TEMPERATURE (°C) 30 20 1100 10 15 20 25 30 35 40 TOTAL SUPPLY VOLTAGE (V) GAIN BANDWIDTH PRODUCT (kHz) GAIN BANDWIDTH PRODUCT (kHz) GAIN BANDWIDTH 5 10 45 VS = ±2.
PAGE 10
LT1638/LT1639 TYPICAL PERFORMANCE CHARACTERISTICS Settling Time to 0.1% vs Output Step 100 VS = ±15V 8 80 AV = –1 4 OVERSHOOT (%) 2 0 –2 –4 AV = –1 –6 60 AV = 5 AV = 1 40 30 AV = 10 20 AV = 1 –8 70 50 0 5 10 100 1000 CAPACITIVE LOAD (pF) Total Harmonic Distortion + Noise vs Frequency THD + NOISE (%) THD + NOISE (%) 0.1 100 Total Harmonic Distortion + Noise vs Output Voltage RL = 10k, f = 1kHz VCM = HALF SUPPLY AV = –1, VS = ±1.5V AV = –1, VS = 3V, 0V AV = 1, VS = ±1.
PAGE 11
LT1638/LT1639 APPLICATIONS INFORMATION Supply Voltage The positive supply pin of the LT1638/LT1639 should be bypassed with a small capacitor (typically 0.1μF) within an inch of the pin. When driving heavy loads an additional 4.7μF electrolytic capacitor should be used. When using split supplies, the same is true for the negative supply pin. The LT1638/LT1639 are protected against reverse battery voltages up to 18V. In the event a reverse battery condition occurs, the supply current is less than 1nA.
PAGE 12
LT1638/LT1639 APPLICATIONS INFORMATION nonlinear common mode rejection. If the op amp is operating inverting there is no common mode induced distortion. If the op amp is operating in the PNP input stage (input is not within 0.8V of V +), the CMRR is very good, typically 98dB. When the LT1638 switches between input stages there is signiﬁcant nonlinearity in the CMRR. Lower load resistance increases the output crossover distortion, but has no effect on the input stage transition distortion.
PAGE 13
LT1638/LT1639 TYPICAL APPLICATIONS The application in Figure 3 utilizes the Over-The-Top capabilities of the LT1638. The 0.2Ω resistor senses the load current while the op amp and NPN transistor form a closed loop making the collector current of Q1 proportional to the load current. As a convenient monitor, the 2k load resistor converts the current into a voltage. The positive supply rail, V +, is not limited to the 5V supply of the op amp and could be as high as 44V.
PAGE 14
LT1638/LT1639 PACKAGE DESCRIPTION Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. DD Package 8-Lead Plastic DFN (3mm × 3mm) (Reference LTC DWG # 05-08-1698 Rev C) R = 0.125 TYP 5 0.40 p 0.10 8 0.70 p0.05 3.5 p0.05 1.65 p0.05 2.10 p0.05 (2 SIDES) 3.00 p0.10 (4 SIDES) PACKAGE OUTLINE 1.65 p 0.10 (2 SIDES) PIN 1 TOP MARK (NOTE 6) (DD8) DFN 0509 REV C 0.75 p0.05 0.200 REF 0.25 p 0.05 4 0.25 p 0.05 1 0.50 BSC 0.50 BSC 2.38 p0.05 2.38 p0.
PAGE 15
LT1638/LT1639 PACKAGE DESCRIPTION Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. N8 Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .400* (10.160) MAX .300 – .325 (7.620 – 8.255) +.035 .325 –.015 8.255 +0.889 –0.381 6 5 1 2 3 4 .120 (3.048) .020 MIN (0.508) MIN .018 ± .003 .100 (2.54) BSC ) 7 .255 ± .015* (6.477 ± 0.381) .065 (1.651) TYP .008 – .015 (0.203 – 0.381) ( .130 ± .005 (3.302 ± 0.127) .045 – .065 (1.
PAGE 16
LT1638/LT1639 PACKAGE DESCRIPTION Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. N Package 14-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .770* (19.558) MAX 14 13 12 11 10 9 8 1 2 3 4 5 6 7 .255 ± .015* (6.477 ± 0.381) .300 – .325 (7.620 – 8.255) .045 – .065 (1.143 – 1.651) .130 ± .005 (3.302 ± 0.127) .020 (0.508) MIN .065 (1.651) TYP .008 – .015 (0.203 – 0.381) +.035 .325 –.015 ( +0.889 8.255 –0.381 .005 (0.127) .
PAGE 17
LT1638/LT1639 REVISION HISTORY (Revision history begins at Rev E) REV DATE DESCRIPTION PAGE NUMBER E 06/10 Updates to Supply Voltage section 11 F 09/10 Units on x-axis of G24 changed from Hz to kHz 10 G 10/11 Updated θJA values for MS8 and DD packages in Pin Conﬁguration 2 Corrected part numbers and revised column title to Speciﬁed Temperature Range in Order Information 3 Deleted Note 10 from Electrical Characteristics 7 16389fg Information furnished by Linear Technology Corporation i
PAGE 18
LT1638/LT1639 TYPICAL APPLICATION The battery monitor in Figure 5 also demonstrates the LT1638’s ability to operate with its inputs above the positive rail. In this application, a conventional ampliﬁer would be limited to a battery voltage between 5V and ground, but the LT1638 can handle battery voltages as high as 44V. When the battery is charging, Amp B senses the voltage drop across RS. The output of Amp B causes Q2 to drain sufﬁcient current through RB to balance the input of Amp B.