LTC2908 Linear Technology, LTC2908 Datasheet
LTC2908
Available stocks
Related parts for LTC2908
LTC2908 Summary of contents
Page 1
... The open-drain RST output state is guaranteed the correct state as long as V1 and/ 0.5V or greater. The LTC2908 also features adjustable inputs with a nominal threshold level at 0.5V. This product provides a precise, space-conscious, micropower and general purpose solu- tion for any kind of system requiring supply monitors. ...
Page 2
... V1, V2, V3, V4 .........................................– 0. ..................–0. ADJ1 ADJ2 ADJ3 .............................–0. ADJ4 ADJ5 RST .......................................................... –0. Operating Temperature Range LTC2908C ................................................ 0°C to 70°C LTC2908I..............................................–40°C to 85°C PIN CONFIGURATION LTC2908CDDB-A1 LTC2908CDDB-C1 LTC2908IDDB-A1 LTC2908IDDB-C1 LTC2908CDDB-B1 LTC2908IDDB-B1 TOP VIEW GND GND ...
Page 3
... V Input Threshold ADJ1 ADJ2 CONDITIONS V1 Input Threshold ADJ1 ADJ2 ADJ3 ADJ4 ADJ5 Input Threshold = 2.5V for the LTC2908-C1, unless otherwise noted. (Notes CONDITIONS RST in Correct Logic State V1 = 5.0V (LTC2908-A1 3.3V (LTC2908-B1 2.5V (LTC2908-C1 3.3V (LTC2908-A1 2.5V (LTC2908-B1 2.5V (LTC2908-A1 1.8V (LTC2908-B1 1.8V (LTC2908-A1 1.5V (LTC2908-B1 ...
Page 4
... TEMPERATURE (°C) 2908 G01 4 = 2.5V for the LTC2908-C1, unless otherwise noted. (Notes CONDITIONS V Less Than Reset Threshold V X More Than –1μ (LTC2908-A1) RST –1μ 3.3V (LTC2908-B1) RST ...
Page 5
... Typical Transient Duration vs Comparator Overdrive 700 T 600 RESET OCCURS 500 ABOVE CURVE 400 300 200 100 0 0 100 COMPARATOR OVERDRIVE VOLTAGE (% OF V LTC2908 www.DataSheet4U.com ADJ Threshold Voltage vs Temperature 0.5080 0.5060 0.5040 0.5020 0.5000 0.4980 0.4960 0.4940 0.4920 –50 – 100 TEMPERATURE (° ...
Page 6
... V2 = 2. 1.5V 0 0.4V ADJ1 ADJ2 0.5 85°C –40°C 0.4 25°C 0.3 0.2 0 RST PULL-DOWN CURRENT, I RST www.DataSheet4U.com RST Pull-Down Current vs Supply Voltage LTC2908-A1/LTC2908- ADJ1 2.5V (A1)/V3 = 1.8V (B1 1.8V (A1)/V4 = 1.5V (B1) 5 ADJ3 0.55V ADJ1 ADJ2 RT33 LTC2908- SUPPLY VOLTAGE, V ...
Page 7
... OUTPUT SOURCE CURRENT, I PIN FUNCTIONS (TS8 Package/DDB8 Package) LTC2908-A1/LTC2908-B1 V2 (Pin 1/Pin 4): Voltage Input 2. The greater of V1 also the internal V . The operating voltage on this pin shall CC not exceed 6V. When in normal operation (V1 > V2), this pin draws approximately 8μA. When this pin is acting as the V (V2 > ...
Page 8
... LTC2908 PIN FUNCTIONS (TS8 Package/DDB8 Package) LTC2908-C1 V1 (Pin 1/Pin 4): Voltage Input the internal V The operating voltage on this pin shall not exceed 6V. When in normal operation, this pin draws approximately 22μA. Bypass this pin to ground with a 0.1μF (or greater) capacitor. V (Pin 2/Pin 3): Adjustable Voltage Input 5. See Table 1 ADJ5 for recommended ADJ resistors values ...
Page 9
... BLOCK DIAGRAMS V1 V ADJ1 V ADJ2 V ADJ3 V ADJ4 V ADJ5 GND TIMING DIAGRAM RST – – – – – – BANDGAP REFERENCE V Monitor Timing X V RTX RST UV LTC2908 www.DataSheet4U.com LTC2908-C1 V1 6μA RST 200ms RESET PULSE GENERATOR 2908 BDa 1V 2908 TD 2908fc 9 ...
Page 10
... All input voltages must be above predetermined thresholds for the reset not to be invoked. The LTC2908 asserts the reset output during power-up, power-down and brownout conditions on any one of the voltage inputs. Ultralow Voltage Pull-Down on RST The LTC2908 issues a logic low on the RST output when any one of the inputs falls below its threshold ...
Page 11
... ADJ R2 (kΩ) actual reset threshold may vary over a specifi ed band 100 (±1.5% for the LTC2908 supervisors). Figure 5 shows 100 the typical relative threshold accuracy for all six inputs 100 over temperature. 100 ...
Page 12
... Adding half of the reset threshold accuracy spread (1.5%) to the ideal 5% thresholds puts the LTC2908 thresholds at 6.5% (typ) below the nominal input voltage. For example, the 5V typical threshold is 4.675V, or 75mV below the ideal threshold of 4.750V. The guaranteed threshold lies in the band between 4 ...
Page 13
... DC/DC 1.0V DC/ 0.1μF 0.1μ 2.15M 86.6k 100k ADJ1 LTC2908-A1 GND LTC2908 www.DataSheet4U.com is the external load capacitance on LOAD . The following formula esti- CC • LOAD is the on-resistance of the pull-up transis- = Max(V1, V2) CC > 1V) at room temperature is estimated • 10 Ω – about 260k. Using 150pF for load ...
Page 14
... LTC2908-B1 GND 2.15M 237k 182k 100k 100k 100k ADJ1 ADJ2 ADJ3 LTC2908-C1 GND www.DataSheet4U.com SYSTEM R3 R4 124k 100k V ADJ2 RST 2908 TA03 SYSTEM V V ADJ1 ADJ2 RST 2908 TA05 SYSTEM R10 124k 86.6k ...
Page 15
... BSC 1.4 MIN (NOTE 4) 0.65 BSC 0.80 – 0.90 1.00 MAX 0.30 – 0.50 REF 0.09 – 0.20 (NOTE 3) 4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 5. MOLD FLASH SHALL NOT EXCEED 0.254mm 6. JEDEC PACKAGE REFERENCE IS MO-193 LTC2908 www.DataSheet4U.com R = 0.115 0.40 ± 0.10 TYP TYP PIN 0.20 OR 0.25 × 45° 0.56 ± 0.05 ...
Page 16
... TRIP 1. 1.685V) TRIP 1. 1.410V) TRIP 0.1μF 0.1μF 182k 100k ADJ1 ADJ2 LTC2908-A1 GND www.linear.com ● www.DataSheet4U.com SYSTEM R3 MANUAL 2.15M RESET BUTTON R5* (NORMALLY OPEN) 10k R4 100k RST 2908 TA04 COMMENTS 4.65 Threshold 2.9V Threshold 4.65 Threshold 4.37V/4.62V Threshold Meets PCI t Timing Specifi ...