ST STM6520 User Manual

Smart Reset

™

with push-button controlled output delay

Features

■ Dual Smart Reset™ push-button inputs, with

user-selectable extended reset setup delay (by two-state input logic): t

■ Push-button controlled reset pulse duration

(no fixed nor minimum pulse width guaranteed)

■ No power-on reset

■ Dual reset outputs

–RST1

- active-low, open-drain

– RST2 - active-high, push-pull

■ Fixed Smart Reset™ input logic voltage levels

■ Broad operating voltage range 1.65 V to 5.5 V,

inactive reset output levels valid down to 1.0 V

■ Low supply current 1.5 µA

■ Operating temperature: –30 °C to +85 °C

■ TDFN8 package: 2 mm x 2 mm x 0.75 mm

■ RoHS compliant

= 6, 10 s (min.)

SRC

STM6520

Dual push-button

TDFN8 (DG)

2 mm x 2 mm

Applications

■ Mobile phones, smartphones

■ e-books

■ MP3 players

■ Games

■ Portable navigation devices

■ Any application that requires delayed reset

push-button(s) response for improved system stability

January 2011 Doc ID15953 Rev 6 1/23

www.st.com

Contents STM6520

Contents

1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2 Device overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3 Pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3.1 Power supply (VCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3.2 Ground (V

3.3 Smart Reset™ inputs (SR0

3.4 User-selectable Smart Reset™ delay (DSR) . . . . . . . . . . . . . . . . . . . . . . . 7

3.5 Reset outputs (RST1

) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

, SR1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

, RST2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4 Typical application diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

5 Typical operating characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

6 Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

7 DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

8 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

9 Package footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

10 Tape and reel information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

11 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

12 Package marking information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

13 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

2/23 Doc ID 15953 Rev 6

STM6520 List of tables

List of tables

Table 1. Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Table 2. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 3. Operating and measurement conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Table 4. DC and AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Table 5. TDFN – 8-lead 2 x 2 x 0.75 mm, 0.5 mm package mechanical data . . . . . . . . . . . . . . . . . 15

Table 6. Parameter for landing pattern - TDFN – 8-lead 2 x 2 mm package . . . . . . . . . . . . . . . . . . 16

Table 7. Carrier tape dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 8. Reel dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Table 9. Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Table 10. Package marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Table 11. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Doc ID 15953 Rev 6 3/23

List of figures STM6520

List of figures

Figure 1. Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 2. Pin connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 3. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 4. RST1

Figure 5. RST2 used for interrupting system power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 6. Timing waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Figure 7. Undervoltage condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Figure 8. Supply current (I Figure 9. Smart Reset™ delay (t

Figure 10. AC testing input/output waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 11. TDFN - 8-lead, 2 x 2 mm package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 12. Landing pattern - TDFN – 8-lead 2 x 2 mm without thermal pad . . . . . . . . . . . . . . . . . . . . 16

Figure 13. Carrier tape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Figure 14. Reel dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Figure 15. Tape trailer/leader. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Figure 16. Pin 1 orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Figure 17. Package marking area, top view. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

output used for microcontroller reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

) vs. temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

) vs. temperature, DSR = VSS . . . . . . . . . . . . . . . . . . . . . . . . . 10

SRC

4/23 Doc ID 15953 Rev 6

STM6520 Description

1 Description

The Smart Reset™ devices provide a useful feature that ensures inadvertent short reset push-button closures do not cause system resets. This is done by implementing extended Smart Reset™ input delay time (t ensures a safe reset and eliminates the need for a specific dedicated reset button.

This reset configuration provides versatility and allows the application to discriminate between a software generated interrupt and a hard system reset. When the input pushbuttons are connected to microcontroller interrupt inputs, and are closed for a short time, the processor can only be interrupted. If the system still does not respond properly, continuing to keep the push-buttons closed for the extended setup time t processor through the reset outputs.

) and combined push-button inputs, which together

SRC

causes a hard reset of the

SRC

The STM6520 has two combined delayed Smart Reset™ inputs (SR0 selectable delayed Smart Reset™ setup time (t

) options of 7.5 s and 12.5 s typ.,

SRC

, SR1) with two user-

selected by a dual-state Smart Reset™ DSR input pin. When DSR is connected to ground, t

= 7.5 s, when connected to VCC, t

SRC

= 12.5 s (typ.). There are two reset outputs, both

SRC

going active simultaneously after both of the Smart Reset™ inputs were held active for the selected t

delay time. The outputs remain asserted until either or both inputs go to

SRC

inactive logic level (for this device the output reset pulse duration is fully push-button controlled, meaning neither fixed nor minimum reset pulse width, nor power-on reset pulse is implemented). The first reset output, RST1 output, RST2, is active-high, push-pull. The device fully operates over a broad V

, is active-low, open-drain; the second reset

range

1.65 to 5.5 V. Below 1.575 V typ. the inputs are ignored and outputs are deasserted; the deasserted reset output levels are then valid down to 1.0 V.

Figure 1. Logic diagram

SR0

SR1

DSR

STM6520

RST1

RST2

AM00434

Figure 2. Pin connections

RST2

SR1

RST1

STM6520

SR0

DSR

AM00435

Doc ID 15953 Rev 6 5/23

Device overview STM6520

2 Device overview

Table 1. Signal names

Symbol Input/output Description

RST1

Output First reset output, active-low, open-drain.

RST2 Output Second reset output, active-high, push-pull.

SR0

SR1

Input Primary push-button Smart Reset™ input. Active-low.

Input Secondary push-button Smart Reset™ input. Active-low.

A dual-state Smart Reset™ input delay selection pin. When

DSR Input

connected to ground, t t

= 12.5 s (typ.). DSR is a DC-type input, intended to be either

SRC

= 7.5 s; when connected to VCC,

SRC

permanently grounded or permanently connected to V

Positive supply voltage for the device. A 0.1 µF decoupling ceramic

Supply voltage

capacitor is recommended to be connected between VCC and VSS pins.

Supply ground Ground

NC No connect (not bonded; should be connected to V

6/23 Doc ID 15953 Rev 6

STM6520 Pin descriptions

3 Pin descriptions

3.1 Power supply (VCC)

This pin is used to provide power to the Smart Reset™ device. A 0.1 µF ceramic decoupling capacitor is recommended to be connected between the V STM6520 device as possible.

3.2 Ground (VSS)

This is the ground pin for the device.

3.3 Smart Reset™ inputs (SR0, SR1)

Push-button Smart Reset™ inputs, active-low. Both inputs need to be asserted simultaneously for at least t

to activate the reset outputs.

SRC

3.4 User-selectable Smart Reset™ delay (DSR)

and VSS pins, as close to the

An input that allows the user to program the setup time (t buttons need to be pressed to activate the reset outputs. Controlled by different voltage levels on the DSR pin: when connected to ground, t t

= 12.5 s (typ.). DSR is a DC-type input, intended to be either permanently grounded or

SRC

permanently connected to V

3.5 Reset outputs (RST1, RST2)

RST1 is active-low, open-drain, RST2 active-high, push-pull. Neither fixed nor minimum output reset pulse duration, nor power-on reset is implemented. Releasing any of the pushbuttons while reset outputs are active, causes both outputs to deassert.

Figure 3. Block diagram

SR0

SR1

DSR

Smart ResetTM

reset logic

selector

SRC

two-state logic

SRC

Oscillator

) for which both the push-

SRC

= 7.5 s, when connected to VCC,

SRC

Output

logic

RST1

RST2

AM00436V2

Doc ID 15953 Rev 6 7/23

+ 16 hidden pages