HA17008RFP Hitachi Semiconductor (acquired by Renesas), HA17008RFP Datasheet - Page 3

• Manufacturer Part Number: HA17008RFP
• Manufacturer: Hitachi Semiconductor (acquired by Renesas)

Functions
Reference differential amplifier and phase compensation
The reference amplifier is a circuit which converts the reference voltage applied to pin 14 through the
external resistor R
mirror and the ladder resistor. Note that this should be used with the polarity of the current flowing in to
pin 14. The reference voltage source provides all of the current flowing into pin 14.
Also, even removing the resistor R
To preserve an appropriate value of the phase margin, it is necessary to increase the value of the phase
compensation capacitance as R
connected to V
connect R
capacitor should be inserted in the reference voltage source to reduce compounded hum and noise. We
cannot recommend the use of noisy 5 V logic power supplies. When a logic control 5 V power supply of
good stability is used for the reference supply, connect a resistor to the reference supply and connect a 0.1
µF capacitor between the reference supply and the resistor contact.
When pin 14 is controlled by a high impedance such as a fixed current supply, phase compensation will not
be possible with the above method. Therefore, provide adequate phase compensation in the frequency band
of the fixed current supply.
5 k , the minimum capacitances should be 15 pF, 37 pF, and 75 pF, respectively. The capacitor is
15
to the negative reference voltage. (Refer figure 2.) If a DC reference voltage is used, a bypass
EE
. If high impedance is required in the reference current source, connect R
14
from a voltage to a current. The converted current is supplied to each bit by a current
Figure 1 Positive Reference Potential Application Example
14
A
A
A
A
A
A
A
A
is increased. For example, if R
1
2
3
4
5
6
7
8
15
10
11
12
will have a minimal influence on precision and temperature drift.
5
6
7
8
9
HA17008R
V
V
CC
13
3
EE
14
15
2
4
16
R
14
I
O
R
R
14
= R
C
15
15
14
is 1 k , 2.5 k , or
(+) V
R
L
REF
HA17008RP/RFP
14
to ground and
3