Datasheet

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LTC6993-1/LTC6993-2

LTC6993-3/LTC6993-4

69931234fb

TYPICAL APPLICATION

FEATURES DESCRIPTION

TimerBlox: Monostable

Pulse Generator (One Shot)

The LTC

6993 is a monostable multivibrator (also known

as a “one-shot” pulse generator) with a programmable

pulse width of 1µs to 33.6 seconds. The LTC6993 is part

of the TimerBlox

family of versatile silicon timing devices.

A single resistor, R

SET

, programs an internal master os-

cillator frequency, setting the LTC6993’s time base. The

output pulse

width is determined by this master oscillator

and an internal clock divider, N

DIV

, programmable to eight

settings from 1 to 2

OUT

DIV

•R

SET

50kΩ

• 1µs, N

DIV

= 1, 8, 64,...,2

The output pulse is initiated by a transition on the trigger

input (TRIG). Each part can be configured to generate posi-

tive or negative output pulses. The LTC6993 is available

in four versions to provide different trigger signal polarity

and retrigger capability.

DEVICE INPUT POLARITY RETRIGGER

LTC6993-1 Rising-Edge No

LTC6993-2 Rising-Edge Yes

LTC6993-3 Falling-Edge No

LTC6993-4 Falling-Edge Yes

The LTC6993 also offers the ability to dynamically adjust

the width of the output pulse via a separate control voltage.

For easy configuration of the LTC6993, download the

TimerBlox Designer tool at www.linear.com/timerblox.

Envelope Detector

APPLICATIONS

Pulse Width Range: 1µs to 33.6 Seconds

Configured with 1 to 3 Resistors

Pulse Width Max Error:

– <2.3% for Pulse Width > 512µs

– <3.4% for Pulse Width of 8µs to 512µs

– <4.9% for Pulse Width of 1µs to 8µs

Four LTC6993 Options Available:

– Rising-Edge or Falling-Edge Trigger

– Retriggerable or Non-Retriggerable

Configurable for Positive or Negative Output Pulse

Fast Recovery Time

2.25V to 5.5V Single Supply Operation

70µA Supply Current at 10µs Pulse Width

500µs Start-Up Time

CMOS Output Driver Sources/Sinks 20mA

–55°C to 125°C Operating Temperature Range

Available in Low Profile (1mm) SOT-23 (ThinSOT™)

and 2mm × 3mm DFN

Watchdog Timer

Frequency Discriminators

Missing Pulse Detection

Envelope Detection

High Vibration, High Acceleration Environments

Portable and Battery-Powered Equipment

L, LT , LT C , LT M , Linear Technology, TimerBlox and the Linear logo are registered trademarks

and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the

property of their respective owners.

69931234 TA01a

LTC6993-2

OUT

DIV

TRIG

GND

SET

800k

3.3V

0.1µF

SIGNAL

ENVELOPE

MODULATED

CARRIER

TRIG

2V/DIV

OUT

2V/DIV

50µs/DIV

69931234 TA01b

80kHz CARRIER

16µs

Summary of content (26 pages)

PAGE 1
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 TimerBlox: Monostable Pulse Generator (One Shot) FEATURES n n n n n n n n n n n n DESCRIPTION Pulse Width Range: 1µs to 33.6 Seconds Configured with 1 to 3 Resistors Pulse Width Max Error: – <2.3% for Pulse Width > 512µs – <3.4% for Pulse Width of 8µs to 512µs – <4.
PAGE 2
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 ABSOLUTE MAXIMUM RATINGS (Note 1) Supply Voltage (V+) to GND.........................................6V Maximum Voltage on Any Pin .................................. (GND – 0.3V) ≤ VPIN ≤ (V+ + 0.3V) Operating Temperature Range (Note 2) LTC6993C.............................................–40°C to 85°C LTC6993I..............................................–40°C to 85°C LTC6993H........................................... –40°C to 125°C LTC6993MP......................
PAGE 3
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 ORDER INFORMATION Lead Free Finish TAPE AND REEL (MINI) TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LTC6993CS6-2#TRMPBF LTC6993CS6-2#TRPBF LTDXJ 6-Lead Plastic TSOT-23 0°C to 70°C LTC6993IS6-2#TRMPBF LTC6993IS6-2#TRPBF LTDXJ 6-Lead Plastic TSOT-23 –40°C to 85°C LTC6993HS6-2#TRMPBF LTC6993HS6-2#TRPBF LTDXJ 6-Lead Plastic TSOT-23 –40°C to 125°C LTC6993CS6-3#TRMPBF LTC6993CS6-3#TRPBF LTFMH 6-Lead Plastic TSOT-23 0°C
PAGE 4
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. Test conditions are V+ = 2.25V to 5.5V, TRIG = 0V, DIVCODE = 0 to 15 (NDIV = 1 to 221), RSET = 50k to 800k, RLOAD = 5k, CLOAD = 5pF unless otherwise noted. SYMBOL PARAMETER Pulse Width Jitter (Note 10) tS CONDITIONS NDIV = 1 MIN V+ = 5.5V V+ = 2.25V TYP MAX UNITS 0.85 0.45 %P-P %P-P NDIV = 8 0.
PAGE 5
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. Test conditions are V+ = 2.25V to 5.5V, TRIG = 0V, DIVCODE = 0 to 15 (NDIV = 1 to 221), RSET = 50k to 800k, RLOAD = ∞, CLOAD = 5pF unless otherwise noted. SYMBOL PARAMETER CONDITIONS tPD Trigger Propagation Delay V+ = 5.5V V+ = 3.3V V+ = 2.
PAGE 6
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 TYPICAL PERFORMANCE CHARACTERISTICS V+ = 3.3V, RSET = 200k and TA = 25°C unless otherwise noted. tOUT Drift vs Temperature (NDIV ≤ 64) 1.5 1.5 RSET = 50k 3 PARTS 1.0 1.5 RSET = 200k 3 PARTS 1.0 0.5 DRIFT (%) 0 0 –0.5 –0.5 –1.0 –1.0 –1.0 50 25 75 0 TEMPERATURE (°C) 100 –1.5 –50 –25 125 50 25 75 0 TEMPERATURE (°C) 100 69931234 G01 1.5 1.5 0.5 0 0 –0.5 –0.5 –0.5 –1.0 –1.0 –1.0 50 25 75 0 TEMPERATURE (°C) 100 –1.
PAGE 7
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 TYPICAL PERFORMANCE CHARACTERISTICS + V = 3.3V, RSET = 200k and TA = 25°C unless otherwise noted.
PAGE 8
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 TYPICAL PERFORMANCE CHARACTERISTICS V+ = 3.3V, RSET = 200k and TA = 25°C unless otherwise noted. 2 LOTS DFN AND SOT-23 1274 UNITS 150 100 50 0 0.98 0.996 1.004 VSET (V) 0.988 1.012 “ACTIVE” = 50% TIMING DUTY CYCLE 250 RSET = 50k ÷1, ACTIVE 200 RSET = 50k ÷1, IDLE 150 RSET = 100k, ÷8, ACTIVE 100 RSET = 100k, ÷8, IDLE 50 0 1.02 RSET = 800k, ÷512 CLOAD = 5pF RLOAD = ∞ 2 3 5V TRIG RISING 3.3V TRIG RISING 3.
PAGE 9
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 TYPICAL PERFORMANCE CHARACTERISTICS + V = 3.3V, RSET = 200k and TA = 25°C unless otherwise noted. 30 3.0 CLOAD = 5pF 50 CLOAD = 5pF 45 RISE/FALL TIME (ns) 20 15 10 2.0 tRISE 1.5 tFALL 1.0 5 0.5 0 0 2 3 4 5 SUPPLY VOLTAGE (V) 6 OUTPUT RESISTANCE (Ω) 2.
PAGE 10
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 PIN FUNCTIONS (DCB/S6) V+ (Pin 1/Pin 5): Supply Voltage (2.25V to 5.5V). This supply should be kept free from noise and ripple. It should be bypassed directly to the GND pin with a 0.1µF capacitor. tolerance and 50ppm/°C or better temperature coefficient. For lower accuracy applications an inexpensive 1% thick film resistor may be used. DIV (Pin 2/Pin 4): Programmable Divider and Polarity Input.
PAGE 11
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 BLOCK DIAGRAM (S6 package pin numbers shown) 5 V+ R1 4 DIV 4-BIT A/D CONVERTER POL DIGITAL FILTER R2 1 TRIG TRIGGER/ RETRIGGER LOGIC S MASTER OSCILLATOR V 1µs tMASTER = • SET 50kΩ ISET Q MCLK OUTPUT POLARITY OUT 6 PROGRAMMABLE DIVIDER ÷1, 8, 64, 512, 4096, 215, 218, 221 tOUT R POR HALT OSCILLATOR IF ISET < 500nA ISET + – VSET = 1V 1V + – GND SET 3 ISET 2 69931234 BD RSET 69931234fb 11
PAGE 12
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 OPERATION The LTC6993 is built around a master oscillator with a 1µs minimum period. The oscillator is controlled by the SET pin current (ISET) and voltage (VSET), with a 1µs/50kΩ conversion factor that is accurate to ±1.7% under typical conditions. 1µs VSET tMASTER = • 50kΩ ISET A feedback loop maintains VSET at 1V ±30mV, leaving ISET as the primary means of controlling the pulse width.
PAGE 13
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 OPERATION Table 1. DIVCODE Programming DIVCODE POL NDIV Recommended tOUT R1 (k) R2 (k) VDIV /V+ 0 0 1 1µs to 16µs Open Short ≤ 0.03125 ±0.015 1 0 8 8µs to 128µs 976 102 0.09375 ±0.015 2 0 64 64µs to 1.024ms 976 182 0.15625 ±0.015 3 0 512 512µs to 8.192ms 1000 280 0.21875 ±0.015 4 0 4,096 4.096ms to 65.54ms 1000 392 0.28125 ±0.015 5 0 32,768 32.77ms to 524.3ms 1000 523 0.34375 ±0.015 6 0 262,144 262.1ms to 4.
PAGE 14
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 OPERATION Monostable Multivibrator (One Shot) Negative Trigger Versions The LTC6993 is a monostable multivibrator. A trigger signal on the TRIG input will force the output to the active (unstable) state for a programmable duration. This type of circuit is commonly referred to as a one-shot pulse generator. In addition to the retrigger option, the LTC6993 family also includes negative input (falling-edge) versions. These four combinations are detailed in Table 2.
PAGE 15
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 OPERATION Changing DIVCODE After Start-Up Start-Up Time Following start-up, the A/D converter will continue monitoring VDIV for changes. Changes to DIVCODE will be recognized slowly, as the LTC6993 places a priority on eliminating any “wandering” in the DIVCODE. The typical delay depends on the difference between the old and new DIVCODE settings and is proportional to the master oscillator period.
PAGE 16
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 APPLICATIONS INFORMATION Basic Operation Step 4: Calculate and Select RSET. The simplest and most accurate method to program the LTC6993 is to use a single resistor, RSET , between the SET and GND pins. The design procedure is a four step process. Alternatively, Linear Technology offers the easy-to-use TimerBlox Designer tool to quickly design any LTC6993 based circuit. Download the free TimerBlox Designer software at www.linear.com/timerblox.
PAGE 17
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 APPLICATIONS INFORMATION Since 625k is not available as a standard 1% resistor, substitute 619k if a –0.97% shift in tOUT is acceptable. Otherwise, select a parallel or series pair of resistors such as 309k and 316k to attain a more precise resistance. TRIG OUT V+ LTC6993 GND The completed design is shown in Figure 7. RMOD VCTRL SET V+ 69931234 F08 2.25V TO 5.5V Figure 8. Voltage-Controlled Pulse Width V+ 0.
PAGE 18
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 APPLICATIONS INFORMATION ISET Extremes (Master Oscillator Frequency Extremes) Coupling Error When operating with ISET outside of the recommended 1.25µA to 20µA range, the master oscillator operates outside of the 62.5kHz to 1MHz range in which it is most accurate. The current sourced by the SET pin is used to bias the internal master oscillator. The LTC6993 responds to changes in ISET almost immediately, which provides excellent settling time.
PAGE 19
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 APPLICATIONS INFORMATION Power Supply Current The Electrical Characteristics table specifies the supply current while the part is idle (waiting to be triggered). IS(IDLE) varies with the programmed tOUT and the supply voltage. Once triggered, the instantaneous supply current increases to IS(ACTIVE) while the timing circuit is active.
PAGE 20
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 APPLICATIONS INFORMATION Supply Bypassing and PCB Layout Guidelines The LTC6993 is an accurate monostable multivibrator when used in the appropriate manner. The part is simple to use and by following a few rules, the expected performance is easily achieved. Adequate supply bypassing and proper PCB layout are important to ensure this. Figure 13 shows example PCB layouts for both the SOT-23 and DCB packages using 0603 sized passive components.
PAGE 21
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 TYPICAL APPLICATIONS Missing Pulse Detector TRIG 25kHz INPUT OUT LTC6993-2 TRIG 2V/DIV 3.3V 0.1µF V+ GND R1 102k SET RSET 402k 64µs OUT 2V/DIV DIV R2 976k DIVCODE = 14 (NDIV = 8, POL = 1) 69931234 TA02b 50µs/DIV 69931234 TA02a Use retriggerable one shot with output inverted. Output remains low as long as retrigger occurs within tOUT = 64µs. 1.
PAGE 22
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 TYPICAL APPLICATIONS RC Servo Pulse Generator Controlled Retrigger Lockout Time Interval TRIGGER 1.5ms PULSE GENERATOR R9 10k TRIG OUT PULSE OUT LTC6993-1 M1 2N7002 5V GND V+ SET DIV C2 0.1µF R1 1M R3 147k TRIGGER PULSE IN R2 280k 1.5ms PULSE OUT 20ms RETRIGGER LOCKOUT INTERVAL OUT R5 100k 5V 20ms RETRIGGER LOCKOUT TRIG RETRIGGER LOCKOUT TIME LTC6993-1 0.
PAGE 23
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 TYPICAL APPLICATIONS Pulse Stretcher 5V R4 4.99k U2 LT1009 2.5V VOLTAGE VARIABLE OUTPUT PULSE WIDTH R1 10k Q4 2N2219A TRIG LTC6993-3 5V 0.1µF Q1 2N2907 – Q2 2N2907 R6 C1 10k 2200pF Q3 2N2219A R16 140k U4 LT1638 + RAMP PULSE OUT STRETCHED PULSE OUT OUT GND V+ SET DIV C4 0.
PAGE 24
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 PACKAGE DESCRIPTION DCB Package 6-Lead Plastic DFN (2mm × 3mm) (Reference LTC DWG # 05-08-1715 Rev A) R = 0.115 TYP 2.00 ±0.10 (2 SIDES) R = 0.05 TYP 0.70 ±0.05 3.55 ±0.05 3.00 ±0.10 (2 SIDES) 1.65 ±0.05 (2 SIDES) 0.40 ± 0.10 4 6 1.65 ± 0.10 (2 SIDES) 2.15 ±0.05 PIN 1 NOTCH R0.20 OR 0.25 × 45° CHAMFER PIN 1 BAR TOP MARK (SEE NOTE 6) PACKAGE OUTLINE 3 0.25 ± 0.05 0.50 BSC 1.35 ±0.05 (2 SIDES) 0.75 ±0.05 0.200 REF 1 (DCB6) DFN 0405 0.25 ± 0.05 0.
PAGE 25
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 REVISION HISTORY REV DATE DESCRIPTION PAGE NUMBER A 7/11 Revised Description section Added text to Basic Operation paragraph in Applications Information section B 1/12 Added MP-grade 1 to 3 15 1, 2, 3, 5 69931234fb Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use.
PAGE 26
LTC6993-1/LTC6993-2 LTC6993-3/LTC6993-4 TYPICAL APPLICATION Consecutive Test Sequencer START TEST SEQUENCE 5V R10 25k DELAY ADJUST 30s R9 274k 2s 2s TO 30s DELAY TEST 1 DELAY TEST 2 TRIG OUT TRIG OUT TRIG OUT LTC6994-1 LTC6993-1 LTC6993-3 GND V+ SET DIV R1 63.4k 5V 0.1µF R2 1000k R3 887k GND V+ SET DIV 5V 0.1µF R6 191k GND V+ SET DIV TEST 3 TRIG OUT LTC6993-3 5V 0.1µF GND V+ SET DIV 5V 0.