CS8140 Cherry Semiconductor Corporation, CS8140 Datasheet
CS8140
Available stocks
Related parts for CS8140
CS8140 Summary of contents
Page 1
... OUT ENABLE lead goes low and the watch- dog signal moves outside its preset window limits. This unique combina- tion of control functions in the CS8140 gives the microprocessor control over its own power down sequence: i.e. it gives the microprocessor the flexibility to perform housekeeping functions before it powers down ...
Page 2
Input Voltage Operating Range .................................................................................................................................................-0.5 to +26V Peak Transient Voltage (46V Load Dump @ 14V V Electrostatic Discharge (Human Body Model)...............................................................................................................................................4kV WDI Input Signal Range ...............................................................................................................................................-0.3 to +7V Internal Power Dissipation ..............................................................................................................................Internally limited Junction Temperature Range (TJ) .......................................................................................................................-40¡C to +150¡C ...
Page 3
... WDI ² V Threshold Frequency C f WDI LOWER f ** WDI(UPPER connected to RESET and V P OUT ** CS8140 only To observe safe operating junction temperature, low duty cycle pulse testing is used on tests where applicable. Package Lead # 7 Lead 24 Lead * 14 Lead TO-220 SOIC Wide PDIP ...
Page 4
V vs. V over 25ûC OUT IN LOAD 5 ENABLE IN 5.0 4 LOAD load 4 6.67W load 3 10W 3.0 load 2.5 2.0 1.5 1.0 ...
Page 5
Typical Performance Characteristics: continued Quiescent Current vs. V over ENABLE (V) IN Watchdog Frequency ...
Page 6
... Thermal shutdown is an effective means to prevent die overheating since the power transistor is the principle heat V OUT source in the IC. Regulator Control Functions The CS8140 differs from all other linear regulators in its unique combination of control features. Watchdog and ENABLE Functions V is controlled by the logic functions ENABLE and OUT Watchdog (Table 1) ...
Page 7
... WDI held low or is too slow after a normal period of operation; ENABLE = LOW ENABLE WDI 0V RESET 0V V OUT 0V 3g: WDI frequency rises above the upper frequency threshold after a normal period of operation; ENABLE = LOW (for the CS8140 only ENABLE WDI 0V RESET 0V V OUT 0V Battery ...
Page 8
... Application Notes Assume that the reset delay must be 200ms minimum. From the CS8140 data sheet the reset delay has a ±37% tol- erance due to the regulator. Assume the capacitor tolerance is ±10%. Closest standard value is 0.82µF. ...
Page 9
... DELAY The output voltage remains long as the CS8140 4 )C DELAY continues to receive the correct watchdog signal. The microprocessor can power itself down by terminating its watchdog signal ...
Page 10
... Figure 7. Application Diagram 110K Figure 8. Applications diagram for CS8140. The CS8140 provides a 5V tightly regulated supply and control function to the microprocessor. In this application, the microprocessor controls its own power down sequence (see text). Application Diagrams V ...
Page 11
Step 3: Increase the ESR of the capacitor from zero using the decade box and vary the load current until oscillations appear. Record the values of load current and ESR that cause the greatest oscillation. This represents the worst case ...
Page 12
... Part Number Description CS8140YT7 7L TO-220 Straight CS8140YTVA7 7L TO-220 Vertical CS8140YTHA7 7L TO-220 Horizontal CS8140YDW24 24L SO CS8140YDWR24 24L SO (tape & reel) CS8140YN14 14L PDIP CS8141YT7 7L TO-220 Straight CS8141YTVA7 7L TO-220 Vertical CS8141YTHA7 7L TO-220 Horizontal CS8141YDWF24 24L SO (internally fused leads) CS8141YDWFR24 24L SO (internally fused leads) (tape & ...