LTC2902-1CGN Linear Technology, LTC2902-1CGN Datasheet
LTC2902-1CGN
Specifications of LTC2902-1CGN
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LTC2902-1CGN Summary of contents
Page 1
... The LTC2902-1 features an open-drain RST output, while the LTC2902-2 has a push-pull RST output. The 43 A supply current makes the LTC2902 ideal for power conscious systems and the part may be configured to monitor less than four inputs. The LTC2902-1/LTC2902-2 are available in the 16-lead narrow SSOP package ...
Page 2
... A CC CONDITIONS V1 Input Threshold V1, V2 Input Threshold V2 Input Threshold V2, V3 Input Threshold V3, V4 Input Threshold V3, V4 Input Threshold V3, V4 Input Threshold ORDER PART NUMBER 16 COMP2 LTC2902-1CGN 15 COMP4 LTC2902-2CGN 14 V2 LTC2902-1IGN 13 V4 LTC2902-2IGN 12 V REF GN16 PART MARKING 10 ...
Page 3
... RDIS Note 5: The output pins RST and COMPX have internal pull-ups typically 6 A. However, external pull-up resistors may be used when faster rise times are required or for V Note 6: The push-pull RST output pin on the LTC2902-2 is actively pulled V2. LTC2902 MIN TYP MAX UNITS – ...
Page 4
... TEMPERATURE ( C) LTC2902-2 RST 2902 F03 Figure 3. Active Pull-Up RST V 1.5V 2902 TD 3V Threshold Voltage vs Temperature 2.850 5% 2.815 2.780 2.745 7.5% 2.710 2.675 10% 2.640 2.605 12.5% 2 ...
Page 5
... Temperature 2.5V 1 1.8V 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 – 60 100 –40 – TEMPERATURE ( C) LTC2902 1.5V Threshold Voltage vs Temperature 1.425 5% 1.405 1.385 7.5% 1.365 1.345 10% 1.325 1.305 12.5% 1.285 1.265 80 100 – 60 –40 – TEMPERATURE ( C) 2902 G05 ...
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... RESET COMPARATOR OVERDRIVE VOLTAGE (% OF V RTX 2902 G14 Reset Time-Out Period vs Capacitance 100m 10m 1m 100 10p 100p 1n 10n 80 100 C (FARAD) RT 2902 G16 RST High Level Output Voltage vs Output Source Current (LTC2902-2) 3.5 3.0 2.5 2.0 1 0.5 1 1.5 I (mA) SOURCE 2902 G19 100 ) RTX ...
Page 7
... Bypass this pin to ground with a 0.1 F (or greater) capacitor. CRT (Pin 5): Reset Delay Time Programming Pin. Attach an external capacitor (C of 4.6ms/nF. Leaving the pin open generates a minimum delay of approximately 47nF capacitor will gener- ate a 216ms reset delay time. LTC2902 V1, V2 V3, V4 100 ...
Page 8
... Bypass this pin to ground with a 0.1 F (or greater) capacitor. All logic outputs (COMP1, COMP2, COMP3, COMP4) are weakly pulled up to V2. RST is weakly pulled the LTC2902-1 and RST is actively pulled the LTC2902-2. COMP4 (Pin 15): Comparator Output 4. Nondelayed, active high logic output with weak pull-up to V2. Pulls high when V4 is above reset threshold ...
Page 9
... BLOCK DIAGRA RESISTIVE DIVIDER V3 MATRIX GND A/D 11 BUFFER V REF 12 BUFFER GAIN ADJUST – + – + – + – + BANDGAP REFERENCE ADJUSTABLE RESET PULSE GENERATOR CRT C RT LTC2902 V1 V2 POWER V CC DETECT LTC2902 RDIS LTC2902-2 V2 COMP1 2 COMP2 16 COMP3 1 COMP4 15 RST 6 RST 6 2902 DB-1 2902f 9 ...
Page 10
... Supply Monitoring The LTC2902 is a low power, high accuracy program- mable quad supply monitoring circuit with four nondelayed monitor outputs, a common reset output and selectable supply thresholds. Reset timing is adjustable using an external capacitor ...
Page 11
... If the bandgap reference becomes invalid (V < 2V typ), the part will reprogram once V CC above 2.4V (max). ( 1mA). REF Monitor Output Rise and Fall Time Estimation All of the outputs (RST, COMPX) have strong pull-down capability. If the external load capacitance (C LTC2902 ( TRIP 11.25 2150 9.4 1780 7 ...
Page 12
... Using a 10k pull- up resistor, the rise time is reduced to 3.3 s for a 150pF load capacitance. The LTC2902-2 has an active pull- the RST output. The typical performance curve (RST Pull-Up Cur- rent vs V2 curve) demonstrates that the pull-up current is somewhat linear versus the V2 voltage and R mated to be approximately 625 ...
Page 13
... Monitor with Unused V2, V3 Inputs Pulled Above Trip Thresholds (5% Tolerance COMP3 COMP2 2 15 COMP1 COMP4 LTC2902 CRT V REF 6 11 SYSTEM RST V PG RESET GND RDIS T1 LTC2902 R3 2.15M 1% 12V V = 11.25V TRIP R4 100k 1% 2902 TA02 R3 464k 1% – –4.64V TRIP R1 R4 16.2k 121k 86.6k 1% 2902 TA03 2902f 13 ...
Page 14
... LTC2902 U TYPICAL APPLICATIO Quad Supply Monitor with LED Undervoltage Indicators, 12.5% Tolerance, Reset Disabled 5V, 3.3V, 2.5V, 1. LED LED 1 16 COMP3 COMP2 2 15 COMP1 COMP4 LTC2902 CRT V REF 6 11 RST GND RDIS LED LED 3.3V 1.5V R1 53. 47.5k 1% 2902 TA04 2902f ...
Page 15
... TYP .015 .004 45 .053 – .068 (0.38 0.10) (1.351 – 1.727) 0 – 8 TYP .008 – .012 (0.203 – 0.305) LTC2902 .189 – .196* (4.801 – 4.978) .009 (0.229 REF .150 – .157** (3.810 – 3.988) 1 ...
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... Programmable Quad Supply Monitor LTC2901 Programmable Quad Supply Monitor Linear Technology Corporation 16 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 Quad Supply Monitor with Hysteresis 5% Tolerance (Supplies Rising) 12.5% Tolerance (After RST Goes High) 5V LTC2902 COMP1 COMP2 10k 3.3V ...