Tone Generator. LT1684 Datasheet

LT1684 Generator. Datasheet pdf. Equivalent

Part LT1684
Description Micropower Ring Tone Generator
Feature LT1684 Micropower Ring Tone Generator FEATURES s s DESCRIPTIO s s s s s s s s s Allows Dynamic.
Manufacture Linear Technology
Datasheet
Download LT1684 Datasheet




LT1684
LT1684
Micropower
Ring Tone Generator
FEATURES
s Allows Dynamic Control of Output Frequency,
Cadence, Amplitude and DC Offset
s Active Tracking Supply Configuration Allows Linear
Generation of Ring Tone Signal
s No High Voltage Post-Filtering Required
s Capacitive Isolation Eliminates Optocouplers
s Low Distortion Output Meets International
PTT Requirements
s Differential Input Signal for Noise Immunity
s User Adjustable Active Output Current Limit
s Powered Directly From High Voltage Ringer
Supply—No Additional Supplies Necessary
s Supply Current: < 1mA
s 2% Signal Amplitude Reference
s Available in 14-Pin SO and DIP Packages
U
APPLICATIO S
s Wireless Local Loop Telephones
s Key System/PBX Equipment
s Fiber to the Curb Telecom Equipment
DESCRIPTIO
The LT®1684 is a telecommunication ring tone generator.
The IC takes a user-generated pulse width modulated
(PWM) input and converts it to a high voltage sine wave
suitable for telephone ringing applications.
The LT1684 receives capacitor-isolated differential PWM
input signals encoded with desired ring output cadence,
frequency, and amplitude information. The LT1684 nor-
malizes the pulse amplitude to ±1.25V for an accurate
signal voltage reference. The cadence, frequency and
amplitude information is extracted using a multiple-
pole active filter/amplifier, producing the output ring tone
signal.
The LT1684 uses its own ring tone output as a reference
for generating local supply rails using complementary
high voltage external MOSFETs as dynamic level-shifting
devices. This “active tracking” supply mode of operation
allows linear generation of the high voltage ring tone
signal, reducing the need for large high voltage filtering
elements.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
Electrically Isolated Ring Tone Generator
DC
PWM
ISOLATION
CONTROLLER
100pF
P1
10k
µC
P2
100pF
10k
IN A GATE+
IN B V+
LT1684
LIM+
OUT
BGOUT
ATREF
COMP1
FB1
100pF
6.8nF 100k
100
1N4001
3k
2k
300k
1µF
5k
AMPIN
4700pF
COMP2
LIM
V
GATE
20pF
1N5817
100
6.8nF 100k
IRF610
100V
+
RING TONE
OUTPUT
0.1µF
( )±100mA
CAPABILITY
IRF9610
–100V
FB1: FERRONICS FMB1601
(716) 388-1020
1684 TA01
1



LT1684
LT1684
ABSOLUTE AXI U RATI GS (Note 1)
Voltages:
Active Tracking Differential Voltage
(GATE + – GATE ) ..................................– 0.3V to 42V
Local Supply Differential Voltage
(V + – V ) ...............................................– 0.3V to 36V
Local Supply
Voltage V + .............. (GATE + – 7.0V) to (GATE + + 0.3V)
Local Supply
Voltage V .............. (GATE – 0.3V) to (GATE + 7.0V)
PWM Input Differential Voltage
(IN A – IN B) .........................................– 7.0V to 7.0V
PWM Input Voltage
Common Mode ................. (V – 0.3V) to (V + + 0.3V)
LIM + Current Limit
Pin Voltage ..................... (OUT – 0.3V) to (V+ + 0.3V)
LIMCurrent Limit
Pin Voltage .................... (V – 0.3V) to (OUT + 0.3V)
All Other Pin Voltages ........... (V – 0.3V) to (V + + 0.3V)
Currents:
LIM +, LIM Current .......................................... – 350mA
OUT Current ....................................................... 350mA
BGOUT Current .................................................... ±10mA
PWM (IN A, IN B) Current .................................... ±5mA
GATE +, GATE Current ....................................... ±20mA
COMP1 Current .................................................... ±1mA
COMP2 Current .................................................... ±1mA
ATREF Current ..................................................... ±20mA
Temperatures:
Operating Junction Temperature Range
Commercial Grade ................................. 0°C to 125°C
Industrial Grade ................................ – 40°C to 125°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
UW U
PACKAGE/ORDER I FOR ATIO
TOP VIEW
IN B 1
COMP1 2
COMP2
LIM
V
GATE
3
4
5
6
ATREF 7
14 IN A
13 BGOUT
12 AMPIN
11 GATE+
10 V+
9 LIM+
8 OUT
N PACKAGE
14-LEAD PDIP
S PACKAGE
14-LEAD PLASTIC SO
TJMAX = 125°C, θJA = 75°C/W (N)
TJMAX = 125°C, θJA = 115°C/W (S)
Consult factory for Military grade parts.
ORDER PART
NUMBER
LT1684CN
LT1684CS
LT1684IN
LT1684IS
2







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