4 Specifications

4.1 Absolute Maximum Specifications

Operating temperature, Ta.............................................................................................. -40 ~ +85ºC

Storage temp, Ts................................................................................................... -50ºC ~ +125ºC

Vdd................................................................................................................... -0.3 ~ +6.0V

Max continuous pin current, any control or drive pin............................................................................ ±20mA

Short circuit duration to ground or Vdd, any pin................................................................................. infinite

Voltage forced onto any pin.................................................................................. -0.3V ~ (Vdd + 0.3) Volts

4.2 Recommended Operating Conditions

Operating temperature, Ta.............................................................................................. -40 ~ +85ºC

Short-term supply ripple+noise............................................................................................... ±5mV/s

Long-term supply stability................................................................................................... ±100mV

Cs range............................................................................................................ 2.2nF ~ 100nF

Cx range................................................................................................................. 0 ~ 50pF

4.3 AC Specifications

Vdd = 5.0, Ta = recommended, Cx = 5pF, Cs = 4.7nF; circuit of Figure 1.1

End of touch

ms

25

Release time - all modes

Tdr

200ms LP setting

ms

200

Response time - LP mode

Tdl

ms

25

Response time - Normal mode

Tdn

ms

10

Response time - Fast mode

Tdf

Both bursts together

ms

3.4

Burst duration

Tbd

ms

350

Start-up time from cold start

Tsu

µs

2

Sample pulse duration

Tpc

Total deviation

%

15

Burst modulation, percent

Fm

kHz

132

Burst center frequency

Fc

ms

150

Recalibration time

Trc

Notes

Units

Max

Typ

Min

Description

Parameter

4.4 DC Specifications

Vdd = 5.0, Ta = recommended, Cx = 5pF, Cs = 4.7nF; circuit of Figure 1.1 unless noted

bits

8

Acquisition resolution

µA

±1

Input leakage current

2.5mA source

V

Vdd-0.5

High output voltage

7mA sink

V

0.5

Low output voltage

V

3.5

High input logic level

V

0.7

Low input logic level

Required for start-up, w/o external reset

circuit

V/s

100

Average supply turn-on slope

@ Vdd = 3.0; 360ms LP mode

µA

45

Average supply current, LP mode*

@ Vdd = 5.0

@ Vdd = 4.0

@ Vdd = 3.6

@ Vdd = 3.3

@ Vdd = 3.0

@ Vdd = 2.8

mA

8

4.5

2.7

2.2

1.8

1.5

1.3

Average supply current,

normal mode*

Notes

Units

Max

Typ

Min

Description

Parameter

*No spread spectrum circuit; Rosc = 18K

Ω

Ω

Ω

Ω

4.5 Signal Processing

Vdd = 5.0, Ta = recommended, Cx = 5pF, Cs = 4.7nF

Towards decreasing Cx load

ms/level

500

Anti-drift compensation rate

Towards increasing Cx load

ms/level

2,000

Normal drift compensation rate

Option pin selected

secs

10, 60,

∞

Max On-Duration

Must be consecutive or detection fails

samples

2

Detect Integrator filter, ‘fast’ mode

Must be consecutive or detection fails

samples

6

Detect Integrator filter, normal mode

Time to recalibrate if Cx load has exceeded anti-detection threshold

secs

2

Anti-detection recalibration delay

Threshold for decrease of Cx load

counts

6

Anti-detection threshold

counts

2

Detection hysteresis

Threshold for increase in Cx load

counts

10

Detection threshold

Notes

Units

Value

Description

10

QT1080 R11.06/0806