PCA2117DUGSSLASHDA datasheet(44/107 Pages) NXP

44 / 107 page

PCA2117

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 4 — 8 April 2015

44 of 107

NXP Semiconductors

PCA2117

Automotive LCD driver for character displays

[1]

No temperature compensation is possible above 105

C. Above this value, the system maintains the

compensation value from 105

C.

8.4.5.3

Example calculation of Voffset(LCD)

Assumed that Tamb = 8 C

1. Choose a temperature factor from Table 35, for example TSB[2:0] = 001, which gives

a slope factor of

0.125.

2. Calculate the decimal value of TD[7:0] with Equation 4:

3. Calculate the temperature compensating factor VT with the appropriate equation from

Table 36:

4. Calculate Voffset(LCD) with Equation 2:

8.4.6 LCD bias voltage generator

The intermediate bias voltages for the LCD are generated on-chip. It removes the need for

an external resistive bias chain and significantly reduces the system current consumption.

The optimum value of VLCD depends on the multiplex rate, the LCD threshold voltage (Vth)

and the number of bias levels.

The intermediate bias levels for the different multiplex rates are shown in Table 37. These

bias levels are automatically set to the given values when switching to the corresponding

multiplex rate.

Table 36.

Calculation of the temperature compensating factor VT

Temperature range (

C) Decimal value of TD[7:0] Equations of factor VT

0 to 48

49 to 96

97 to 143

144 to 230

[1]

231

T40

C

–



–

TSB

TSA



–



C

–



C

–



–

TSB

TD[7:0]

–

 TSA



–



C

–

C





TD[7:0]

–

 TSB



–

CT50 C





TD[7:0]

–

 TSC



CT 105 C



TSC



TD[7:0]

143

–

 TSD



105

CT



TSC



TSD



–

0.6275

-------------------



–



–

0.125

–



5.625

offset LCD



5.625

0.03 V



0.169 V

Table 37.

Bias levels as a function of multiplex rate

Multiplex

rate

LCD bias

configuration

Bias voltages

1:18

1⁄4

VLCD

VSS

1:9

1⁄4

VLCD

VSS

1:2

1⁄3

VLCD

VSS

---V

LCD

---V

LCD

---V

LCD

---V

LCD

---V

LCD

---V

LCD

---V

LCD

---V

LCD

---V

LCD

---V

LCD

---V

LCD

---V

LCD

PCA2117DUGS/DA Datasheet(PDF) 44 Page - NXP Semiconductors

PCA2117DUGS/DA Datasheet(HTML) 44 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL