ATMEL U2510B-M Datasheet

All-Band AM/FM Receiver and Audio Amplifier

Description

The U2510B is an integrated bipolar one-chip AM/FM
radio circuit. It contains an FM front end with
preamplifier, FM IF and demodulator, a complete AM

Features

 Superior FM strong signal behavior by using RF AGC

receiver, an AF amplifier and a mode switch for AM, FM
and tape. This circuit is designed for clock radios and
portable radio-cassette recorders.

 DC mode control: AM, FM and tape

U2510B

 Soft mute and HCC for decreasing interstation noise

in FM mode

 Excellent AFC performance (level controlled, both

polarities available)

 Level indicator (LED drive) for AM and FM

Block Diagram

FM osc.

tank

87 6

AFC

FM

front end

FM

AM

front end

RFAGC

AM/FM

and

15

IF BPE

14 16

AFC

control

AM IF

amp. and

detect.

IF

AGC

AGC

21 13 20 19 1

FM ant.

FM RF

BPE

AGC

AM

ant.

AM osc.

tank

12

11

10

5

V

Ref

FM RF

tank

9

AGC

Voltage stab.
mode control

 Wide supply-voltage range and low quiescent current
 High AF output power: 1 W
 Electronic volume control
 Electronic AF bandwidth control (treble and high cut)
 Output stage for headphone and speaker drive

(Replaceable)

V

S

AM

IF

FM IF

amp.

Level
indic.

226

FM

discr.

22 18

Power

amp.

AF preamp.

Volume

Mute
HCC

28

27

3

25
23

24

4

S

AM

FM

2

Tape

V

S

AFC mode

Figure 1. Block diagram

LED

V

S

Treble Vol

13912

Rev. A3, 23-Feb-01 1 (15)

U2510B

Order Information

Extended Type Number Package Remarks

U2510B-M SDIP28

U2510B-M__T SDIP28 VS < 6 V supply voltage

Pin Description

Mute

FM-discr

Vol ctrl in

AMOsc

FM-AFC

FMOsc

V

FMtank

AMtank

FM-AGC

FMin

FE-GND

AM/FM

IFout

CF

Ref

1

2

3

4

5

6

7

8

9

10

11

12

13

14

14812

Figure 2. Pinning

Pin Symbol Function

1 Mute Mute voltage output, time constant (C23),

2 FM-discr FM discriminator filter connection, ceramic

3 CF Audio negative feedback input. Blocking

4 Vol ctrl in Input for volume control voltage

mute depth and threshold adjustable by load
resistance (R3)

resonator or equivalent LC-circuit

capacitor (C8) determines the audio amplifiers
low-end cut-off frequency

28

27

26

25

24

23

22

21

20

19

18

17

16

15

AF-GND

AFout

V

S

Ripple in

AFin

AM/FM detect

V

AGC/AFC

AFC switch

IF-GND

LED drive

V

Treble in

FM-IFin

AM-IFin

Mode ctrl
switch

Pin Symbol Function

5 AMOsc AM oscillator tank circuit input, recommended

6 FM–AFC AFC diode connection, coupling capacitor

7 FMOsc FM oscillator tank circuit input, recommended

8 V
9 FMtank FM RF tank circuit connection, recommended

10 AMtank AM RF tank circuit connection, recommended

11 FM-AGC FM AGC voltage output, time constant (C20).

12 FMin FM RF input (common-base preamplifier

13 FE-GND FM front-end ground
14 AM/FM

15 Mode ctrl

16 AM-IFin AM IF input, input impedance = 3.1 k
17 FM-IFin FM IF input, input impedance = 330 
18 V
19 LED drive Level indicator output

20 IF-GND IF ground
21 AFC switch AFC function control input:

22 V

23 AM/FM

24 AFin Audio amplifier input, input resistance

25 Ripple in Ripple filter connection. Load capacitance

26 V
27 AFout Audio amplifier output
28 AF-GND Ground of the audio power stage

IFout

switch

Treble in

AGC/AFC

detect

load impedance approximately 2.5 k

(C19) determines the AFC characteristic
(holding range and slope)

load impedance approximately 3 k
Regulated voltage output (2.4 V)

Ref

load impedance approximately 3 k

load impedance approximately 20 k

Loading this pin by a resistor (to GND) will
increase the FM AGC threshold, grounding
this pin will switch off the FM AGC function

transistor), recommended (RF) source
impedance approximately 100 

AM/FM IF output
(collector output of the IF preamplifier)

Mode control input:

Pin | Function
open | F M
Ground | AM
VS (R4 = 10 k) | Tape

Treble control voltage input

(open-collector output, LED drive)

Pin | Function
open | AFC off
Ground | f
V

S

AGC/AFC voltage, time constant adjust (C10),
input impedance approximately 42 k

AM/FM detector output, the load capacitor
(C11) in conjunction with the detector output
resistance (7.5 k) determines the (FM)
deemphasis as well as the (modulation)
frequency response of the AM detector

approximately 100 k coupling capacitor
(C9) determines the low frequency response

(C12) determines the frequency response of the
supply-voltage ripple rejection

Supply voltage input

S

| f

OSC
OSC

> f

in

< f

in

Rev. A3, 23-Feb-012 (15)

Terminal Voltages

Test circuit: Vin = 0

Pin Symbol

1 Mute voltage (R3 = 0) V
2 FM discriminator V
3 Negative feedback V
4 Volume control input (S4 = A) V
5 AM oscillator V
6 FM AFC V
7 FM oscillator V
8 V

Ref

9 FM RF tank V
10 AM input V
11 FM AGC V
12 FM input V
13 Front end ground V
14 AM/FM IF output V
15 Mode control switch V
16 AM IF input V
17 FM IF input V
18 Treble control input (S5 = A) V
19 LED V
20 IF ground V
21 AFC switch (S3 = off) V
22 AGC (AM)/AFC (FM) V
23 Detector output V
24 AF input V
25 Ripple filter V
26 Supply voltage V
27 AF output V
28 AF ground V

U2510B

Voltage/V

VS = 3 V VS = 6 V

AM FM TAPE AM FM TAPE

1
2
3
4
5
6
7

V

8

9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

– 1.6 – – 1.6 –
– 1.0 – – 1.0 –

1.2 1.2 1.2 2.6 2.6 2.6

2.4 2.4 2.4 2.4 2.4 2.4

2.4 – – 2.4 – –
– 1.9 – – 1.9 –
– 2.4 – – 2.4 –

2.4 2.4 2.4 2.4 2.4 2.4
– 2.4 2.4 – 2.4 –

2.4 – – – 2.4 –
– 0 – – 0 –

1.4 – – 1.4 –

– – – – – –

2.9 2.7 – 5.9 5.7 –
0 – 2.9 0 – 5.7
0 – – 0 – –
– 0.7 – – 0.7 –

2.4 2.4 2.4 2.4 2.4 2.4

0 0 0 0 0 0

1.2 1.2 1.2 1.2 1.2 1.2

1.5 1.2 – 1.5 1.2 –

1.5 1.2 – 1.5 1.2 –

1.5 1.5 1.5 1.5 1.5 1.5

2.7 2.7 2.7 5.3 5.3 5.3

3.0 3.0 3.0 6.0 6.0 6.0

1.2 1.2 1.2 2.6 2.6 2.6
0 0 0 0 0 0

Rev. A3, 23-Feb-01 3 (15)

U2510B

Absolute Maximum Ratings

Parameters Symbol Value Unit
Supply voltage V
Power dissipation P
Ambient temperature range T

Electrical Characteristics

S

tot

amb

13 V

900 mW

–20 to +75 °C

VS = 6 V, T

= 25°C, test circuit (figure 16), unless otherwise specified

amb

Parameters Test Conditions / Pins Symbol Min. Typ. Max. Unit
Supply voltage range V
Oscillator stop voltage V

S
S

2.5 9 * V

2.2 V

Operating temperature range T –20 +75 °C
Supply quiescent current Vi1 = Vi2 = V4 = 0;

AM (S2 = AM)
FM (S2 = FM)
TAPE (S2 = Tape)

Regulated voltage Pin 8 V

I
I
I

Ref

S
S
S

4.0

6.5

2.2

2.4 V

Audio amplifier Vi3 (Pin 24), test point: Vo (Pin 27) f = 1 kHz
AF measuring range: 30 Hz to 20 kHz, S2 = Tape, S4 = A, S5 = A

Input resistance Pin 24 R
Closed loop voltage gain GV

= 20 log (Vo/Vi3)

af1

Vi3 = 10 mV GV
Output voltage Vi3 = 100 mV, S4 = B V
High–end cut-off frequency fc (–3 dB)

S5 = B
Supply-voltage rejection ratio SVRR = 20 log (V

V

= 200 mV,

hum

f

= 200 Hz, S4 = B SVRR 32 dB

hum

hum/Vo

)

Noise voltage S4 = B, Vi3 = 0 V

j

af1
o

f

c

f

c

n

100 k

40 dB

0.7 3 mV
13

0.8

kHz
kHz

300 1000 V

AF output power THD = 10 %, RL = 8 

VS = 4.5 V
VS = 6.0 V
VS = 9.0 V

P

o

P

o

P

o

400

225
420

1000

mW
mW
mW

Distortion Po = 50 mW, RL = 8  d 0.6 %
FM section, Vi2 = 60 dBV, fi2 = 98 MHz, fm = 1 kHz, dev. =  22.5 kHz, f

= 10.7 MHz,

iIF

AF measuring range: 300 Hz to 20 kHz, S2 = FM, S1 = A, S6 = B, test point: VD (Pin 23)
FM front-end voltage gain GVFM = 20 log (V

S1 = B, Vi2 = 40 dbV GV
Recovered audio voltage Pin 23 VD
Detector output resistance Pin 23 R

iIF

/ Vi2)

Do

FM

30 dB

af

85 mV

7.5 k

Detector output distortion dev. =  75 kHz

Vi2 = 60 dBV

Vi2 = 105 dBV

THD
THD

0.5

0.8

* U2510B-M__T: max. 6 V

mA
mA
mA

%
%

Rev. A3, 23-Feb-014 (15)

Electrical Characteristics (continued)

U2510B

VS = 6 V, T

= 25°C, test circuit (figure 16), unless otherwise specified

amb

Parameters Test Conditions / Pins Symbol Min. Typ. Max. Unit
AM rejection ratio m = 30% AM
RF sensitivity (S+N)/N = 26 dB

(S+N)/N = 46 dB

Limiting threshold (-3 dB) V

RR

V

i2

V

i2
i2

Mute voltage Test point: Mute

Vi2 = 0
Vi2 = 60 dBV

V
V

mute
mute

Mute depth Referred to V0 at Vi2 = 0

S6 = A
S6 = C

AFC holding range f

> fin, S3 = A, S6 = A

OSC

V

 10 dBV

i2

Vi2 = 20 dBV

Vi2 = 80 dBV
LED current I
Oscillator voltage eZ

= 2.5 k Pin 7 V

load

AM section Vi1 = 60 dBV, fi1 = 1.6 MHz, fm = 1 kHz, m = 30%, f

MD
MD

FHR
FHR
FHR

LED

OSC

= 455 kHz,

iIF

AF measuring range: 300 Hz to 20 kHz, (S2 = AM, S1 = B, test point: VD)
AM front end voltage gain GVAM = 20 log (V

iIF/Vi1

)

GV

AM

Vi1 = 20 dBV, S1 = A
Recovered audio voltage V
Detector output resistance Pin 23 R
Detector output distortion Vi1 = 60 dBV

Vi1 = 105 dBV
RF sensitivity (S+N)/N= 10 dB

(S+N)/N= 26 dB

(S+N)/N= 46 dB
AGC figure of merit referred

to V

D af

Vi1 = 105 dBV, voltage

drop (V

) = –10 dB FOM 100 dB

D af

IF input resistance Pin 16 Z
LED current I
Oscillator voltage Pin 5 V

D af1

Do

THD
THD

V

i1

V

i1

V

i1

i

LED

OSC

25 dB

9

22

3 dBV

1.8

0.4

26
20

no AFC

 180
 220

5.5 mA

180 mV

25 dB

70 mV

7.5 k
1

3
0

16
35

3.1 k

5.5 mA

160 mV

dBV
dBV

V
V

dB
dB

kHz
kHz

%
%

dBV
dBV
dBV

Rev. A3, 23-Feb-01 5 (15)