ADP1046ACPZ-R7 datasheet(29/96 Pages) AD

29 / 96 page

Data Sheet

ADP1046

Rev. 0 | Page 29 of 96

Temperature Linearization Scheme

The ADP1046 implements a linearization scheme based on a

preselected combination of thermistor (100 kΩ, 1%), external

resistor (16.5 kΩ, 1%), and the 46 μA current source for best

performance when linearizing measured temperatures in the

industrial range.

The required NTC thermistor should have a resistance of

100 kΩ, 1%, such as the NCP15WF104F03RC (beta = 4250,

1%). It is recommended that 1% tolerance be used for both the

resistor and beta values.

Reading the Linearized Temperature

Reading Register 0x1B (updated every 10 ms) returns the current

temperature according to an internal linearization scheme. See

Table 1 for the specified accuracy of these measurements. The

temperature reading result is represented in 8-bit decimal format

in °C; therefore, the temperature range for this reading is from

0°C to 255°C.

OVERTEMPERATURE PROTECTION (OTP)

If the temperature sensed at the RTD pin exceeds the threshold

programmed in Register 0x2F, the OTP flag is set. The response

to the OTP flag is programmable using Register 0x0B[7:4].

An RTD trim is required to make accurate temperature readings

at the lower end of the RTD ADC range to account for tolerances

in the NTC thermistor and the external resistor. This trim results

in a more accurate measurement for determining the OTP

threshold (see the RTD/OTP Trim section).

OVERCURRENT PROTECTION (OCP)

The ADP1046 has several OCP functions. CS1 and CS2± have

separate OCP circuits to provide both primary and secondary

side protection.

CS1 OCP

CS1 has two protection circuits: CS1 fast OCP and CS1 accurate

OCP (see Figure 38).

CS1 Fast OCP

CS1 fast OCP is an analog comparator. When the voltage at the

CS1 pin exceeds the (fixed) 1.2 V threshold, the CS1 fast OCP

flag is set. A programmable blanking time can be set to ignore

the leading edge current spike at the beginning of the current

signal (leading edge blanking).

A debounce time can be programmed to improve the noise immu-

nity of the OCP circuit. When the CS1 fast OCP comparator is

set, the OUTA, OUTB, OUTC, and OUTD PWM outputs are

immediately disabled for the remainder of the switching cycle.

These outputs are reenabled at the start of the next switching

cycle. This function cannot be bypassed.

CS1 Accurate OCP

CS1 accurate OCP is used for more precise control of overcurrent

protection. With CS1 accurate OCP, the reading at the output of

the CS1 ADC (Register 0x13) is compared to a programmable

OCP limit. The CS1 accurate OCP value can be programmed

from 0 to 31 decimal using Register 0x22[4:0]. If the CS1 reading

exceeds the CS1 accurate OCP limit, the CS1 accurate OCP flag

is set. The CS1 ADC is asynchronously sampled, and the readings

are averaged every 2.62 ms to make a fault decision. The flag

response is programmed in Register 0x08.

VIN

OUTA

OUTD

OUTC

OUTB

CS1

ADC

1.2V

FAST OCP

COMPARATOR

CS1 FAST

OCP

FLAG

PWM

CS1 ACCURATE

OCP FLAG

CYCLE-BY-CYCLE

SHUTDOWN

OUTA

OUTB

OUTC

OUTD

SR1

SR2

OUTAUX

FLAGS

CS1

FAST OCP

BYPASS

REG 0x27[4]

CS1

FAST OCP

DEBOUNCE

REG 0x27[7:6]

CS1

FAST OCP

BLANKING

REG 0x22[7:5]

FLAGIN

CS1 ACCURATE

OCP SETTING

REG 0x22[4:0]

SHUTDOWN

CYCLE

TIMEOUT

REG 0x27[1:0]

ASYNCHRONOUS

2.62ms AVERAGING

Figure 38. CS1 OCP Detailed Internal Schematic

ADP1046ACPZ-R7 数据表(PDF) 29 Page - Analog Devices

ADP1046ACPZ-R7 数据表(HTML) 29 Page - Analog Devices

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

数据表下载

链接网址

ADP1046ACPZ-R7 数据表(PDF) 29 Page - Analog Devices

ADP1046ACPZ-R7 数据表(HTML) 29 Page - Analog Devices

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

数据表 下载

链接网址

数据表下载